I believe it helps. It sure couldn’t hurt. I have come to the point where I don’t want to stack any more unless absolutely necessary and if I do, then I want a copper wrap to help with the heat.
The drivers are in parallel. The batteries are in parallel series only because I need the voltage thru the chips. Otherwise, as long as the drivers are master slave, the batteries can just be parallel for a 3.xx volt led. The master has the zener mod, to protect the mcu and the 7135 chips do need extra heat sinking. If not, the light gets dim very quickly, due to reduced 7135 output. The last time I tried using .010" thick copper sheet and wrapped the drivers, soldering the copper to the tabs of the chips and it seemed to help a lot.
Do you want to combined the output’s and then run the emitters hooked in parallel or do you want each individual driver to run one emitter independent of the other (but still controlled from only one MCU)?