Sounds good to me :+1:
I already purchased all the parts for both the led and fet boards x 6.
Ordered almost everything from Arrow and a few pieces from Mouser. Mouser charged me 8 bucks for shipping for what would fit in a soda bottle lid. 
Oh boy. Damn it.
That must have cost a kidney in shipping.
2 for me please. If there is any fet switches left. 
1. BlueSwordM
2. BlueSwordM
3. Inkidu
4. Shirnask
5. TomE
6. TomE
7. Kawiboy1428
8. Kawiboy1428
9. MRsDNF
10. MRsDNF
11. Inkidu
Thanks. 
Just in time MRsDNF. Better late than never.
2 more left I think.
Yep, 2 more left.
I should be receiving the PCBs next week.
I just realized one thing: I only have one spare Omten switchā¦
Iām going to have to order some.
I buy a bunch of these. Itās a 3 pack so keep that in mind.
https://www.fasttech.com/p/9627747
They have a discount going on too. I just ordered some for I believe it was $1.08 for a 3 pack ordered 2.
Ordering more gets you into the 3 or more volume discount but its still a good deal.
The last order I placed a few months back was a 5 pack for these but the ledās were orange.
They looked cool but had a higher drain. Orange isnāt as efficient.
Iāll add that the resistor might need to be changed to something higher, the orange was too bright.
I was talking about these actually:
I meant the physical switch to activate the gate of the FET.
Yeah I know, I just rob the switch.
If I want to drop one in something else like a V11R for a lighted switch, I just drop it in. Takes care of both needs.
Iāll buy another one.
Two by two they marched.
I ordered a couple boards from OSH park but I canāt see myself being able to solder such small components. I was ordering the 17mm high-amp switch pcb by Pilotdog68 (great name) so why not add a few more. Would a stencil be an option for the GFS16? The attachment battery/super capacitor would still be a hurdle though.
Yes, but since itās more complicated compared to an LED MCPCB, making a DIY stencil will very hard.
Iāll have to solder these components by hand, which Iāve already had practice off, so shouldnāt be hard at all, unlike the boost driver.
After waiting long time for all component to arrive, I finally start building Gfs16 switch to add to my Gxb172 driver. I use Oshpark to order pcb, and I order 0.8mm thick pcb so it will fit in switch. If it is too thin, easier to add some tape to make thicker. First I solder the mosfet pcb.
The battery fresh from order measures at 2.5V. I am using white omten1288 switch. To make switch, first I use hot air and solder the lfpak33 mosfet on the opposite side of the pcb, and then I solder the smaller component on the top. All this is good and easy to solder after practising from Gxb172. Next to make sure I do not short battery, I tape my tweezer in tape. Then, I flatten the lead on the battery and straighten it, and cut using sharp cutter.
This is result. A little bit of balance and soldering is actually quite easy. I measure circuit after to make sure no shorts on soldering. Then finally I solder on white switch.
For the led board, I decide to use white led as light, and red led as low battery indicator. I experiment with resistor and decide to use 27k for white, and 7.5k for red led. I begin with side with small component. This is where I make my first mistake! I only order 2 N-fet, which is a big mistake, because I move too fast and knock the two tiny fet off the table!!
I almost give up but after 20min search, I finally manage to find them. So I advise everyone to buy more component then they need!
Soldering is not too difficult, except for 3 tiny mosfet. I recommend soldering slightly to the side. Then hot air and flux to reflow easily.
This is complete led side. I use 0603 red and white led from Aliexpress shop. I do quick test and it lights up! However I run out of time and will continue later.
Today I complete my Gfs16 mosfet tail switch and led tail light with battery low indicator!! Here is the result. After soldering both pcb, first I test the led board.
I use warm white led for nice glow effect. Since this is good, I solder both board together, + to + and - to -. Then I understand why loneoceans make oval cutout on pcb, since the battery need to stand up and fit through. This was perfect fit!!
I use thick copper spring from noctigon and I use lfpak33 mosfet in the middle. Finally I test low battery indicator with power supply and it work very well, turning red when battery is low, and turn off below 3V. very happy.
When I first measure battery, it is at 2.5V. Then once I finish the Gfs16, I connect it to 4V powersupply and let it charge battery for half day, and the battery voltage is now about 3.0V and going up. Because it look like it is charging through 2.2k resistor, it will take a while to charge full.
Next, I realize I make big mistake.
The Convoy S2+ is not all the same! Sad that my gray S2+ is actually using black rubber boot and not working with stainless steel switch!! So other people trying, you need to be careful! Lucky that I bought clear rubber boot in the past so I use that instead.
Before I install into tailswitch, I make some measurement.
Resistance Measuremenet
- Original convoy switch - 47.2milliOhm (lowest measurement, click a few times get very different result..)
- Original convoy switch with wire bypass 22 awg - 15.2milliOhm
- Gfs16 mosfet switch with battery at 3.0V - 6.4milliOhm
This measurement include the spring. I use power supply to generate 5A constanct current and measurement taken using multimeter for voltage, to find actual resistance.
My tiny battery for above experiment is 3V, maybe waiting a bit longer will be 3.3V, which drive gate of mosfet in tailswitch, so maybe in the future performance is even better. This result is good enough that I do not use bypass spring.
Last I adjust Gxb172 and add bypass resistor of 220 ohm using 0805 resistor solder on the jumper pad (ground side) and the center spring.
Finally my entire Gxb172 flashlight is COMPLETE!
Review for gfs16:
This project is easier to solder together than Gxb172. The hardest one is soldering the tiny mosfets on the led board. The rest is easier than Gxb172. I am not sure why schizobovine have problem with battery, since mine work first time.
Same as Gxb172, I recommend to use magnification to solder with smaller solder tip, thin solder wire. I only use hot air for the lfpak33 mosfet.
Before assemble, I suggest to make sure lfpak33 have no short, battery have no short, and led light system voltage working with power supply. For me I use oshpark 0.8mm pcb for both and they fit Convoy S2+ good.
I recommend the hobby maker to order more tiny mosfets before you blow them on the floor, and I recommend making sure you buy the correct Convoy s2+ light to make sure it fit the stainless steel switch! Make sure you handle tiny battery carefully! Also I use very thin wire (awg30?) to solder + and - pad together. I make sure I keep the switch screw tight, but not overtight to prevent pcb from breaking because it is not as strong as aluminum washer.
Difficulty - 6/10
Cost - 5/10
Result - 9/10! Very nice! I remove one point so it is not perfect so loneoceans can motivate to improve it 
I recommend loneoceans add more led on the tail to make ring of light, but I understand how it may have no space since need two bank of leds, and any smaller is harder to solder.
Big thank and appreciation to loneoceans for this cool project and for everyone here who also make their own and inspire me to build this successful project!! 
Is it too late to get on the list for a switch?
No, not at all.
Thereās one left.
Actually, in my experience the result is much better with a clear rubber boot. The stainless switch requires 3-4x as much light/power and still barely shows through the tiny gasket. Itās not worth it.
Please put me down for 1 blueswordm.
If still available I would like to purchase one.