All three run together ?
I think its bit difficult to find one driver for series/parallel configuration with lots of current
with boost driver from TaskLED (3 emitter 6V in series or 3 emitter 12V in series) but not run at full power
best option maybe one driver for each emitter
maybe this thread have some useful info for you
You can use driver from Buck LED driver TaskLED, but buying 3 of them will be a lot off money
