What is there to compare with the upper end of Chinese front bike lights? Something like a Rockbros 1800 (5200mAh).

Raveman PR1600? Twice the price – twice as good?
Moon meteor storm – now onto £120?
Bontrager Ion Pro?
One of the lezyne mega / super drives?

Only real requirements are it can be remotely charged whilst running (from a top tube bag) and there is a GoPro compatible mount for it (to attach below my wahoo).

Mainly for commuting as I tend to use a head mounted light for MTB.

Only real requirements are it can be remotely charged whilst running (from a top tube bag)

Why not get one with an external battery? Cheap head unit, decent battery (as that’s where cheap lights tend to suffer).
Or if you want a self contained one, just get one with a decent life so you don’t need to worry about changing during use (which for a commute light really shouldn’t be an issue, it’s not as if you want a billion lumens so 4+ hours should be easy from a charge)

Halfords do a 1600 lumen for £60 with the ability to fit below your wahoo. The bonus of buying in the uk is that if its defective you will be able to sort the matter out, without the hassle of dealing with china

My summer set up – two of these: Sofirn IF25A BLF Anduril Powerful USB C Rechargeable LED Flashlight 21700. search Ali-ex…. Easy bar mount. Helmet mount from Exposure works well. Built in charger. Quick battery swap. Was £24 – 27 or so each.

Only real requirements are it can be charged whilst not burning my house down