Too much; Not enough

I'll go first:

1. Too much incidental combat (monsters standing around, not sniping or summoned via linedef actions)
2. Not enough lift actions used as doors

Man, aint that the truth. All the different mapping formats are so confusing. I know that's just the tip of the ice berg for a source port developer like you.

1. too much "medium" lighting (sector lighting 112-160)
2. not enough health

1. Too many "standards" across ports that are really just re-inventing whats already been done better previously.
2. Not enough EDGE maps.

Take my upvote good sir

Too many WADs.
Not enough time.

to add to this:

The artistic maps are nice showmanships of artwork but the geometry can often get in the way. Plus some people just don't have resource-rich computers to play some of these maps even if they are GZDoom. There should be cooperation for the boom-compatible ports cause I like to play some of those Boom-compatible slaughtermaps with weapon mods in ZDoom ports and I cannot do that with some sets like igetityoulikehordesofmonstersandsuperrichdetailbutplayabilitywiseitsverylimitedandiliketoplayslaughtermapswithweaponmodstospiceupgameplayandexperiencebuticantplayatagoodfpslevelifyoustackfivehundredhealthbonusesontopofonetointentionallymakethegamelaginmypreferredportforweaponmods.