+1 for restic. I’ve been using it for four years now and have never encountered an issue, including during my yearly restore practice run.
As far as B2 bucket encryption is concerned, I wouldn’t trust it as far as I can throw it. Quite honestly, it could just be a fancy checkbox on their website without any actual encryption, and we wouldn’t be able to tell. Either way, a compromise of Backblaze would put your data at risk.
Oh you mean MiB as in mebibel?
With LibreWolf you also have to trust