I figure it will measure brighter since it’s a very high drain battery, but I wouldn’t think you’d see the difference with your eyes - compared to a decent high capacity cell like the Shockli 5500/Keeppower 6000.
Battery length/spring compression should not have a noticable effect. Pretty minimal. The dual spring design makes it minimal. If it were a single spring then compressing the coils until they touch acts like a wire bypass and reduces resistance.
Frankly, I would not concern myself with pushing the amperage higher on this light (like with high drain cells). It’s pretty close to the limit as is.
I looked at HKJ’s comparator at the Efest 4200. The 2016 model looks like this and is pretty comparable to the Ijoy high drain.
The 2017 version looks like this and is a bit weaker. I think Efest has stayed with this for 2018 as well (HKJ has not tested a 2018 version)
So I don’t think your running a super high drain battery, just a regular high drain. It’s not putting out the big voltage at a 10A load like the Ijoy, Aspire or Golisi. So it’s probably fine.
Still, the SST-40 is a pretty new led so we don’t know how long it will handle these maxed out levels. Might be fine in the long run or might burn out. No one knows.
The 50.2 is a chunky emitter not known for throw. It’s a lot more light, but not as much throw.
I think the xpl-hi IS about the same size die as a sliced SST-40. The SST-40 might be a little brighter. IDK if anyone has done the swap. Surely someone tried.
Personally i would compare the throw of the XHP50.2 to a XML2 yea not great but not the worse plus you get the extra output over what the XML2 has. Because of the flip chip design it performs better than the standard XHP50.
You could use an 18650 and lead sleeve to make it “feel” higher quality.
Seriously though, weight is just thermal mass (which is definitely good for the xhp50.2…) but anyone who takes a midsize thrower backpacking will likely appreciate the light weight.
I never understood where the heavier = better quality came from.