With one of those and the bar light I think you are in danger of setting trees on fire as you ride through the woods!
But think of the lumens you’d get, a decent forest fire must be visible from space surely?
Not a criticism of the op, but seriously who needs or even wants 8k lumens?
Yes my old mk3 maxx d is a bit meagre without a head torch but that’s half of what makes night rides enjoyable, you get to see things (literally) in a different light to day rides and things you wouldn’t otherwise see, like the couple of badgers and an otter I saw on my last outing, which would have scarpered long before an 8k light would have illuminated sublimated them.
FWIW op, I’ve got a Diablo I use as my head lamp, it spends most of the ride in low**, which is fine* for most woodsy singletrack, medium of its reasonably technical and kicked up to max for a couple of really awkward bits. Lasts me 3-4 hours of ride then a few more because I forget to charge it.
*well until someone turns up with 8k strapped to their bars and burns out my retinas.
**it’s a sync one so low is set to 8hrs, medium 2.5, high 35 minutes and whatever luminosity that translates to