I'm a Pocket Casts user, and see that it was one you tried.

Pocket Casts lets you select the episode order (as well as do things like group by season). I think it's pretty common to be able to add RSS feeds by putting them in the directory search field, and PC does this as well.

I've had absolutely zero problems using Pocket Casts to add custom Patreon feeds, and to listen to episodes in the other they came out.