I am in the process of testing 50W RGB LED driver boards.
They are the same size as 20W LEDs, but larger flood enclosure is needed due to generated heat.
The driver works very close to the top limit of some of the parts, so dedicated power supply should be used for each flood (will probably fit in the flood itself.)
@24V, blue LED runs @50% (red and green is fine.) @27V, blue is pretty much at @100% and this is the voltage I would recommend.

I will have few boards available for those who are willing to do thorough tests.