Nothing wrong with the batteries from mtb batteries!
Mine died after a winter’s use. Happy to accept that it was probably bad luck as most people are happy with them and they’d just self discharged over the summer.
But for the money the solarstorm box, panasonic or samsung cells and a nitecore digital charger is the best VFM as you will only ever have to replace dead cells rather than whole packs in the future, if they ever die which is significantly less likely as they’ll always be balanced if you use a separate charger.
Only downside is the box is bigger by a few mm in all directions than the silicone cases, I did think of getting a second one and cannibalising it for the protection circuit and putting it in a silicone case with a cheap 2s2p holder (or just relying on the batteries protection).
You can get decent (i.e. not nasty cheap spotty solarstorm) beam patterns from chinese lights these days, you can even get the mtbbatteries ones.
I’ve got a genuine lumenator on my head and a nitefighter BT70 diffused on my bars. I actually prefer them both on low to medium on most trails even in groups as it doesn’t mess with my peripheral vision so much and it’s still plenty of light.