Alright, thanks for the replies People!
I cranked them up early and checked temps. I actually have two of these kits in a 5x5. Ambient room temp is about 26c/79f. As I stated above I have decent airflow under the boards and to be a bit more clear I have one 6" clip fan above and at one end of each slate, (blowing down and across). With my cooling setup like this I'm seeing Board Temps at 43c/109f on the hot end, (opposite of the fan side). While the Slate on that 'hot' end is roughly 7c cooler than the board, about 36c/97f. On the side I have the 6" clip fans attached the boards are reading around 40c/104f with the slate above the board reading about 8c cooler 32c/90f. This is with no TIM and the driver installed on the center top of each slate, (standard kit build). If I'm not mistaken I think I read that the Operating Temp max on these boards is around 90c. Is this correct? If so I should be good. Probably just going to add a second 6" clip fan on each end that doesn't have one now.
My initial thinking was that this driver would be outputting roughly 170w per board since the info on GL said the dimmer would range from 33-338w. And I wasn't sure if that would be a little much. I'm just not sure how voltage and all that affects LEDs like it does a CPU for instance. But if I'm understanding and assuming correctly, this driver doesn't output more than 320w even if the dimmer can hit 338w? Or is this just a non-issue no matter? If my calculations are correct at 338w output that would put each board at 3.13amps / 54v. But at 320w output it would be sitting around 2.96-2.97amp / 54v.
Question about TIM. I'm very versed in using TIM on computer builds as I regularly build custom water loops. I've been overclocking CPUs and GPUs for years now. My first question is, would thermal tape be a better alternative to thermal paste on boards like this? And what thickness would be best. When dealing with PC cooling and transferring heat from Chip to Heatsink its best to use as little as possible because you get best thermal transfer when only filling in the micro scratches from the machining process. So I'm curious to know how much TIM and what sort of TIM you people who use it actually use.
Thanks again for the info. This site has been a wealth of knowledge when it comes to lighting, for me. So again, thank you everyone!
Edited for initial incorrect slate temp.