I think that most people would not understand the advantage of such a driver. And IMO that’s why there is no driver like that… 
Developing such a driver would not be lucrative as only a few people would buy it.
Several people here develop drivers without commercial gain in mind. Oshpark Projects
Well the advantage of turning ON/OFF 7135's is no PWM's. So 8 chips: high of 2.8A, 4 chips: 1.4A w/clean no PWM's, 2 chips: 0.7A w/clean no PWM's, 1 chip: 350 mA clean....
Also it's been discussed the nature of PWM's is toggling full power ON/OFF which has the same higher voltage demand as 100% power. So if you run with just 4 chips, the voltage demand is lower, therefore the cells will last longer, etc... All around more efficient, less stress... How much? Dunno, but theoretically much better - true direct amps, no PWM's - beautiful thing. I like the idea for sure...
Don’t forget that you can still do PWM on a single 7135 as well, if you are so inclined. I think this will give a much lower moonlight than a stock qlite (for example) is capable of.
I guess somebody should get motivated to design the hardware. I’ve got a fair idea of how to handle the modifications to the STAR firmware as well.
I think PPtk bit off too much - should have left off the whole USB thing... Probably much easier then.
Unfortunately I have no time to tackle with eagle (not to mention programming) but this old idea should’t be too hard to become reality. Especially as OSH park can be used to fabricate pcb boards and parts of existing firmware(s) could be used. Most of us are by now more than capable to reflow few components and program attiny.