Ah. I had a feeling, but it was not obvious until I was adding some feeds via a different routine last night: I haven’t checked all of them, but I’m 99% sure that all of the “403” feeds are set to only be accessible to logged-in users.
I then wonder if there’s any way (for me) to provide some authn token on the RSS feed, or if NewsBlur can support user-specific feeds/bsky support in this case?
As well, it would be nice if the OPML import did not fail the entire import/batch for singular feed addition failures.