So I picked up a J5-V2 Tactical Flashlight as a possible bike headlight, on the basis of a 750 (“max output”) lumen LED, zoomable beam, and use of standard 18650 lithium cells (rather than USB charging). The geometry required to stick it on the Tour Easy remains a puzzle, but an az-el dingus replacing an upper fairing mount may work well enough.
Anyhow, it seems the LED in this flashlight fell on the floor during assembly, where the (silicone?) LED emitter lens picked up a remarkable amount of dirt:
The inside of the front focusing lens carries an array of scratches or, perhaps, a greasy fingerprint that serves the same purpose:
All vendors tell you to contact them before posting a critical review, although they often don’t provide much in the way of contact information. I sent a note with photos to J5 through their website’s contact info; having not heard anything after three days, I’ll fire up the Amazon return process …