Can/could you lower the mat to reduce noise, splash?
Perhaps make it like a stair step, use a pleated cartiage with higher surface area etc?
Or use several mats?
the old mop/yarn mats for breeding /eggs layer, fry etc. These would serve as great media.
Upgrading the light would also make it very effective.
Health of the corals looks great, no skimmer methods work, I've long suggested it.
Let the plants do the work.
works great on fish only aquariums, both FW and Marine.
pleated old cartiage filter that has more surface area.
A big plus in reducing the heat. I
You can use a small diversion to go to a denitrifyer
I could go on, but these are just a few of the DIY notions that can be added.
There are many versions that could be done by clever folks.
You might consider a more efficient light though, try some T5's.
I think surface area is also playing a larger role here. The more texture difference on the mat, the better, whether at the larger or small scales.
PAR is a much better parameter to compare one bulb, or light source from another with growth studies.
Also, do not compare wet weights, unless you also do the Dry weight comparison's for algae biomass produced. Our eyeballs can easily be deceived when it comes to algae and it's 95% or so water.