Bubble plates were used, first, effectively by Royal Exclusiv, to reduce turbulence allowing the use of short wide bodies:
The use of a bubble plate for home sized skimmers, is not as effective as the hype would have you believe. Since its introduction by Royal Exclusiv, it has pretty much become a "me too" type of thing. A sales gimmick. What affects efficiency, air flow, bubble size and contact time. Increasing the water flow at first increases effeciency, then causes it to drop off, the best increase is more air flow w/o increasing the water flow-- only really possible in an air driven skimmer (with air pump.) A off the shelf skimmer, with the recommended pump, and set up and adjusted per the instructions is going to be the most efficient for that particular skimmer.
Anecdote would tell you that "did this mod, and my skimmer kicks ***," but without a quantitative analysis of the TOC content of the skimmate, the anecdote is meaningless. Quantitative analysis is out of the capability of the home hobbiest.
Theoretically, one could let a given volume of skimmate sit for a specified time period, and then evaluate the nitrate content of the skimmate, and possibly use this as a gauge for skimmer performance--however it would have to be in controlled circumstances-- eliminating all other variables. Again, not really within the capability of the home hobbiest.
The moral of the story is: Buy a quality skimmer (ok perhaps an anedotally based choice,) correctly sized for the application (based on system volume and flow rate through the skimmer) use the specified pump, set it up according to the instructions (not anecdote) and the skimmer will perform at its most efficient. For the price of quality skimmers these days, let the skimmer manufacturers spend the money on R & D.
Jim