It’s a very interesting and complex idea. Will you match PAR on each coral? That is lower intensity of some fixtures or dim them so the PAR is the same as that could have more impact that the fixtures themselves and would only be related to the size and only show that more PAR is better for some corals. Then how about the PUR, will you look at that at all using a senseye perhaps?
Which leads into the next question of spectrum. Are you doing to run all channels equally? I fear this could become a “what spectrum grows coral best” over fixture review. Many of these run quite white, more than many people prefer, so how will you handle that? Attempt to match PAR and spectrum closely as possible on the coral? Fixture 1 might outperform fixture 2, but if #1 is really white it becomes a question of is that fixture better or was the more white light better and would fixture 2 have done as well if turned down the blues (or up the whites) and what does it matter since no one will run fixture 1 that white?
Just food for thought.