I am guessing you are already on top of this, but just in case I wanted to suggest that you aim for Podcasting 2.0 compatibility:

https://podnews.net/podcast/i4ji5 https://github.com/Podcastindex-org/podcast-namespace/blob/m... https://podcastindex.org/

Also I tried searching for my top 5 podcasts, and none of them came up which was disappointing. Neat idea though.