Imo parsers should be allowed.

They check chat logs anyways when people are reported so obviously if someone's like oh your only pull 800 dps you scrub they'll know they are abusing said system. You can already call people out without them why not at least add an idividual parser so you can at least see what your doing.
And on that note if your pulling 400-500 dps as a dps in any of the extremes you can't even get mad for being kicked your just pulling the whole group down. Pf or df that's just harming the party over all. In dungeons if people pull bad dps tough luck chances are your gonna clear it anyways so suck it up and carry them through. In extremes however if you can't meet the dps check cause someone's pulling that low your only gonna solve that 1 way.