Shouldn't be too difficult to replace the prismatic cells in those ayups with some more recent higher capacity ones. (Add the usual 'if you have to ask then you don't know what you're doing' warning to this).
I have run my solarstorm off a 2s lipo (rc cars) temporarily. But always wanted to have better low volt indicator / protection so never made it into a regular thing. Never did find a good off the shelf solution for that.
Also bought a 4 cell 7.4v holder, so I could run some high capacity 18650s (3400mah) and just have backup cells for quick changes, but the springs would bounce the cells out of contact intermittently and the ss lights just turn off immediately following loss of power. Not great to happen mid trail.
In the end, I feel like current Gloworm level lights are pretty well priced for their spec. Easy to find the components cheaper, but putting them together and getting the UI, by remotes, and safety circuits etc. all set up is where the secret sauce is at. Probably really nice as 24h race setups and what I would buy if I was doing those. Exposure seem a bit over priced (and integrated cells make it less appealing to me when paying that much), but some people like them. Magicshine could be another option. The higher end Lezyne lights seem pretty good. Light and Motion are exxy but look to be decent specced too. A few others out there if you research.
My money stays with the decent bargain lights I posted above though. Olight do good stuff (no affiliation etc). That giant was just a runout sale light, but great for the price.