The concept is sound, but the syndicate part is becoming increasingly hostile to maintain. I used to have scripts that auto-posted to twitter, facebook and reddit. Over the last two years, almost all of those broke due to API paywalls or aggressive bot detection.

I've found that "POSSE" is shifting more toward "Publish on Own Site, Manually Link Elsewhere."

Paradoxically, ActivityPub (mastodon/fediverse) is the only place where true automated syndication is still reliable. I think the future of POSSE isn't trying to hack together API keys for walled gardens, but treating your personal site as a fedi instance so the syndication is native.