True but making MCH a better buff feeder is only one of the possible ways to fix it, it’s not the only way. Of the 4 selfish jobs only really SAM is a good buff feeder (compared to truly burst heavy jobs like PCT or NIN) yet MCH is the only one that suffers for its position in the meta despite 3 out of 4 being relatively poor buff feeders. Because VPR and BLM are given enough damage to compensate for their poor buff feeding capabilities.
You could also fix it with the simple “every skill gets 100 potency” change (not actual numbers) where its profile doesn’t change but it simply does more damage. You are correct that if selfish DPS are ahead in rDPS they are actually deceptively stronger than they actually are (doubly so if they are ahead in cDPS) but right now MCH just suffers from many problems at the same time. If your aim is improvement of buff feeding your suggestions are all good
But of course this still kinda goes way beyond my original point that basically just amounts to “using aDPS to prop MCH up against buffing classes is useless info. If you want an Omni job comparison of total contribution to the raid rDPS is your best bet”