Reddit sends podcast traffic that behaves better than almost any other surface. People arrive because a subject interested them, they arrive on a desktop or a phone with sound on, and they finish episodes at rates that make paid social look wasteful.
It is also the surface most likely to remove your post, shadow-ban your account, and add your domain to a filter you will never be told about.
The rules are not written down anywhere in one place, but they are consistent enough to state plainly.
Nobody wants your episode. They want the thing in it. A post that says "new episode out now" is an advert in a room where adverts are removed on sight. A post that says what you found, in the post itself, with enough substance to be discussed without leaving Reddit, is a contribution. The link belongs in a comment or at the end, and it converts better there anyway.
Account age and comment history are the filter. A three-week-old account whose only posts are links to one domain is the exact shape of a spam account, and automated moderation treats it as one. An account that has been reading and replying in a subreddit for months can post a link and be fine.
Every subreddit is a different country. The rule that gets you removed in one is the rule that does not exist in another, and the only reliable way to know is to read the sidebar and to have been there a while. Posting the same thing to twelve subreddits in an hour is the single most reliable way to be removed from all twelve.
Self-promotion ratios are real, whether or not they are posted. The common expectation is that most of what you contribute has nothing to do with your own work. Communities that do not state this still enforce it socially, which is slower and harder to appeal.
Timing matters less than people think and consistency matters more. A subject that interests a community interests it on a Tuesday.
What does not work, reliably: buying upvotes, posting from multiple accounts you control, and asking friends to vote. Reddit's detection for this is old, well-tuned, and it acts on the domain as well as the account, which means a mistake here costs you the surface permanently rather than the post.