I thought I’d start a thread to compile and show off mods people have made for the GT Nano since the current nano discussions thread has a lot of other stuff to sort through.
Please share your mods to the GT Nano below!
I like the form factor of the 10180 Nano but wanted Anduril 2 instead of Narsil. I also wanted to check the heat path was adequate to avoid turning my emitter blue.
To do the firmware flashing you’ll need some pretty small soldering iron tips. I used a J02 T12 tip (bent and 0.2 mm wide at the very point) for the very fine soldering onto the mcu.
I started off by opening the light at the head. Luckily nothing in this light is glued which is nice for modding. The stock wires from the driver to the mcpcb are very thin (maybe 26 gauge or thinner) and the holes are pretty big so you’ll be able to replace them with some pretty thick wire (relatively). I used 24 gauge.
Once you desolder the mcpcb wires, the driver dropped right out since mine was only held in the light by the mcpcb wires.
My MCPCB had almost no thermal paste underneath it!
With my confidence in a reliable heat path waining, I decided to reflow my emitter because the thermal pad appeared to not have solder while the other pads had solder protruding from them.
My photo doesn’t show the lack of solder very well but it looked like there was an air gap as shone in some other peoples’ photos.
There was solder on the middle thermal pad when I desoldered the LED but it wasn’t a lot. Some bare copper was still showing at one end of the thermal pad.
The mcpcb is so small that I used some tweezers to reflow it since I only ordered a hotplate yesterday. Well actually I used two pairs of tweezers, one of them to pick up the led 
The driver is a double layered one with the Attiny85 on the bottom layer and the Switch, fet, red led, and 7135 on the top piece. The switch is very happy 
I had heard complaints about the LED not being very bright so I swapped its resistor. The old resistor was a 9840 ohm 0402 resistor and I swapped in a 124 ohm one which made my switch LED much brighter. (I would have picked a higher value one but I only had a couple of random 0402 resistors I got from soldering practice kits). I didn’t take any pictures of this bit but the switch led is an 0603 (I think) sized red LED that is pointing downwards, away from the switch boot so most of the led’s light isn’t even reaching the switch boot normally, which is part of the reason it appears so dim.
The MCU is a QFN package Attiny85 which means our usual SOIC clip is incompatible. They probably chose this package because it’s a smaller size than the SOIC package and helps them fit everything into the smaller footprint. The smaller size and close pins made this a trickier than usual flashing job.
I had been hoping that the 6 posts between the two board could be used for flashing since they’re visible from the battery compartment without removing driver and would make flashing much. Unfortunately they’re the usual 2,3,4,5,6,8 pins on a SOIC attiny85.We need pins 1,4,5,6,7,8 for flashing so I did some analysis to figure how each pin is connected and this is what I came up with.
I still needed wires to RESET and PB2 to flash software so I connected them using some very thin wire.
I used single strands from 28 gauge wire and soldered them to the two remaining pins.
They weren’t super difficult to connect using a very thin tip and lots of flux. It helped that RES was on the edge of the attiny and SCK had an inactive pin beside it so bridging the two wouldn’t be an issue.
I plugged in my cables to the USB flashing adapter, connected it to my computer and flashed anduril 2 without any issues. I used the SC36 version of anduril since this light has the same MCU pin layout.
I then assembled everything and here’s what the aux led light looks like.
All in all, a fairly straightforwards project without too many hurdles to get over if you have a bit of luck soldering individual strands to your attiny wires.
Feel free to ask questions if you have any!
Ugh excuse any errors. It’s late here so I’ll proofread my post tomorrow.