I also noticed slow dl speeds some weeks ago, and had to restart the download. Nearly did not install it out of growing frustration. But it worked out in the end.
Oh, I thought it was my NoScript addon that was messing that up, good to know. Gonna try again in a couple of days or just go the Fedora -> rebase route.
Yeah rebase will probably be the fastest way. Otherwise maybe you can find a torrent of bazzite? Looks like they have several different images so that may be hard to find