I suspect they have flagged users that get filtered differently. I've been in comment threads where people say very similar things as myself with all the same keywords and I'll get a message days later about a submission being hidden due to some violations.

Depends on how you do it. If it’s E2E then according to this comment from March 2020 it goes through: https://news.ycombinator.com/item?id=23110664

I tried it during the election and it didn't work. Have uninstalled it since then so don't know if things have changed.

Seems a bit random. That worked for me and also a 1337x.to link worked but I've had the latter blocked in the past - it's a torrent tracker.