I've never heard of that being done before. I have no idea what effect that would have on the diffusers, and the other concern would that the algaecide would not be distributed equally in the shallow areas where it is needed the most.
Would the algaecide not be distributed in the same way as dye is when you dump it on the edge?
Yes it would, but it still wouldn't help. When you apply the algaecide you are supposed to use a strong stream to break up the mats so the algae is exposed to the algaecide. If left in mats, the outer pieces of the mat are exposed, but it has a hard time penetrating the mats because water doesn't flow easily through the mats to carry the algaecide with it.
You can do an experiment by just taking the boat out in the pond and dumping the algaecide in the plume. BUT you'd have to trickle it in to get the same effect.
I still applaud the out of the box thinking, but I don't think it will work as well as you are expecting. Only one way to know for sure is to try it, at the very worst you will either stall out the compressor or plug the diffuser. Both are just mechanical things that can be fixed or repaired.
You will have to meter the algaecide in somehow so you don't overdose the area. Some fish are more sensitive to copper than others and if you see some dead fish, after doing it then that is what I'd attribute the deaths to.