Rodatty I certainly done 6 channels and channels might be possible, but I haven't tried it. The simulator works well...

Rodatty It must use a constant current driver NOT a constant voltage driver. All leds are like this, if you use constant voltage it will destroy your leds very quickly. If you want to run at 30W say, then the led requires voltage is approx 30V so a 1amp driver would give you 30V x 1A = 30W. The 1A constant current unit should be rated to provide 30-40V to allow for some variation in the led voltage due to batch and running temperature.

Rodatty I am a lighting designer. The answer is probably! As long as there is good thermal contact between all 3 COB's you will probably get away with it as long as the COBs come from the same batch. If the temperature of each COB is different then the hottest one will go into thermal run away and hog more and more current until it burns out (because they have a negative temperature coefficient). Adding a series resistor to each COB will help a little but the resistor will dissipate about 1 watt even if its only 1 ohm, so this isn't a great solution, as 1 ohm won't help much anyway.The best thing to do is to fit say the 50W parts, in parallel on the same heatsink, but run them only at 30W each. Then if one COB runs a bit hotter it won't be running out of spec. I would be pretty confident you will get away with this.Rod