When using multiple constant current drivers for High Power RGB LEDs, connect Vo- together?
EDIT after OP clarifications
Basically, you suggest to to the following :



simulate this circuit &ndash; Schematic created using CircuitLab
Yes, it should work, BUT you can see that the current of the 3 channels flows through one single Vo- wire from the strip to the power supply. It may, or may not exceed what it can safely sustain... But if the current on each channel is kept within the specifications of the strip, it should work as expected
The drawback here is the high current into the wire that comes back from the LED strip. And it's also a single point of failure. If it breaks, all LED are affected. And if the current if high enough on one channel, the small resistance of the wire may induce a variation on intensity into the 2 other channels. ( if you use small wires for instance)
The second suggestion is :



simulate this circuit
The advantage of this is a complete isolation. Not a single point of failure.
The drawback is the cost of the wiring.