I only use both while riding in very dark roads to avoid deer. But that's a rare occasion. And I still have 2 or 3 spare EBR headlights, so not as much a worry to me I suppose.
"Love is the never ending act of forgiveness" -Peter Ustinov
2017 EBR 1190SX
2000 Buell M2
1995 Buell S2 (x2)
On my '14 SX, I can see that when both lights were on at once via the Hi-beam flash button, that although both lamps are lit, I could see that the individual emmiters were dimmed slightly and didn't really light things up any better, just pull in your flash to pass on a dark country road and see . I too went with the "individual heat sink theory" and was not initially concerned about an overheating issue so I moved forward with keeping the low beam on during hi beam. Even though LEDs don't pull much power, I guessed that perhaps the OEM wiring harness was sized at an absolute minimum causing the lights to dim when both were on. To test that, I ran 14 gauge jumpers from a fully charged (and on a charger at 14.6v) battery directly to the headlight Hi and Low beam connectors. I found that still, when both lights were on, they both dimmed and I saw no difference than just pulling in the Flash to Pass. My "guess", without a disassembly of the lights themselves to confirm, is that there is some shared circuitry and/or common circuit board Trace etc, for both lights that is bottle-necking full power to both at once. I've shelved the project until I can find a crashed light to dissect.
mike
Rigid ignites fit nicely on the second screws up on the radiator covers. I have my switch hooked to the base of the left mirror stalk.
While it's still not really what I really want, I adjusted the low beams, basically too high and the high beams lower, about half way between, it's better than adjusted by the book.
Since the low beam has a MUCH broader spread, and it "seems" that the actual brightness between the two are at least similar, with the wider/broader light spread of the low beam, the low beam adjusted a bit higher, lights up MUCH more road than if adjusted per the book.
I wish I could install lights like I have on my XB12 (HID's), those are...nice.
Mike