@Mark Piezo, I wouldn’t risk it.
I would get this driver instead:
https://www.aliexpress.com/store/product/17mm-Driver-for-SST40-4-modes-0-1-3-30-100-max-current-output-5000mA-Temperature/330416_33007449093.html
Same firmware, but lower current.
Yes, I would recommend the 5 ampere version for the SST-20 in general.
For no mode memory, I would ask Simon for one without it.
Exactly. A lot of people aren’t in the 21700 craze and will continue to buy 18650/18350 batteries and hosts even if they gradually buy 21700 battery because contrary to what you might think there is a non negligeable difference which you can feel when carrying a 21700 flashlights in a pocket (pants) compared to 18650.
There is no 21350 battery, if you want a shorter quad, a 18650/18350 quad host like the S2+ is still the way to go and probably even for many years.
I hope that you will consider to make one beside your new 21700 flashlights.
That’s the problem with Simon’s new drivers. No options like mode groups or memory toggle. After using the Biscotti drivers in his lights, these new drivers are a major step down in UI. The only advantage is the higher current.
If you want no memory and an SST-20 try the 7135x8 biscotti driver. Better UI and still very bright. If you want high current and the ability to disable memory LED4power’s LD-A4 driver has various current options and customizable settings like memory. I haven’t tried the LD-A4 yet but it’s on my list of stuff to try.
That’s it, discussion is over 
Anyway, I could appreciate something which would center the battery within some size range. It would be really nice e.g. to fit a 18650 battery to a 26650 light without adapters, rattling, etc.
How should it work? I don’t know, but I have seen some 3D printed springy marvels already, what I were not able to imagine :sunglasses:
One more thing: Is it legal to have so much lumens in a so small light, like in the M3? 
Mine just has arrived. It has approximately the same brightness as the L6, but in a wider hotspot 
Brilliant!
@Mark, tu peux l’acheter ici:
https://led4power.com/product/ld-a4-2-12amp-17mm-constant-current-led-flashlight-driver/
You can buy it in the luink above.
This lens fits almost perfectly to the front ring of the M3. I think, finally, I have the perfect high beam, which has enough power to complement the Busch & Müller Ixon Space
Actually, it would be nice to have a Convoy bike light, with a bike compatible beam pattern. (something like in the above link)
SST20’s seem to get hot fairly quickly even with 2.8A drivers, surely 5A would be pushing things too far?
Seems like it’d survive if heat sinked properly 
Agreed, my “6A should be fine” was based on a bit of hopeful dreaming. In an M21A, 5A is about the most I’d do.
Yeah.
You’d need the best host possible, and some great thermal paste.
Simon, are your 5 amp and 6 amp drivers designed for forward clicky or reverse clicky switches? Or can they be used in both?
They can be used with both. The Convoy S2+ is the proof of that.
However, it is more optimal for the rest of us to use reverse switches.
Keep in mind based on his photos of his new lights his newer higher powered lights using these drivers have the springs bypassed which will be highly recommended in your own builds.
Ordered the S21A and S11 this morning, the order status said "extended processing time 7-11 days". However, it then shipped later this afternoon.
both
Je ne suis pas d'accord! Please don't take this as an offence BlueSwordM but there is no high current reverse clicky switch available that can sustain current drain above 8A without causing a significant increase in resistance in your entire current path. Thus, you lose output over the forward clicky switch. Another side effect is the terrible noise these kind of switches will make when applying too much current. Personally, I prefer the forward clicky with momentary turbo and a locked mode when fully pressing the tailcap switch. I have no problems when people ask for a reverse switch version but I do not agree with the phrase that for the rest of us it is more optimal to use reverse switches. ;-)
Simon, What about L21A with XHP50.2 ?
In this case, I would prefer the L6 style. Switch is on-off (that is a forward clicky, if I am correct), and an electronic switch for the UI. If there are enough space in the tailcap, they could be next to each other, or if it is possible, the electronic switch could be a ring around the on-off switch.
I am very used to change mode after I have turned on the flashlight, maybe this is why I hate forward clicky.
xhp50.2 can be installed in L21A