You can roughly estimate the value of the current (1*li-ion)
1.5A*13V=19.5W (24W eff 75%)
19.5W/4.08V=4.78A (6.4A eff75%)
19.5W/3.7V=5.3A (7.02A eff 75%)
19.5/3.3=5.9 (7.87A eff 75%)
in reality my multimeter showed 7,8A and flashlight turning off turbo
all thats being said and done doesn’t make me feel good about my purchase 
Same here.
Did I buy an R&D work-in-progress?
it’s a nice light. I liked the form factor, that is why I purchased it. But with all this, springs, driver, etc and the possible switch going bad issue, it is the ONLY light I ever regretted purchasing. (some regret buying the Cometa CPF Italia, I absolutely love the light!)
Wouldn’t the 26350 just have more voltage sag than the bigger 26650? The little 26350 batteries at 3.8 volts are probably dipping down below 3 volts with an 8 amp load causing the low voltage protection to kick in.
The 26650 are bigger and probably doesn’t let thd voltage sag down as low under the same loads.
It seems the 26650 are what you want to run in the light normally The 26350 are just to wow your friends at how bright a tiny light is. Not very practical.