This is a huge minus.
At first it appeared that a big plus for me was that it Tumbleweed uses the same version of Thunderbird as my default Linux Mint. This was a sore point for me concerning Manjaro. I couldn’t drop back to my reliable Mint if needed with the Thunderbird files, because Manjaro was on a different version and the files were upgraded, if I needed to turn back. Before it was as simple copying the .thunderbird directory to the other system. It even worked with Manjaro. At current time this is what I’ve seen suggested in my searches…but it doesn’t work in Tumbleweed.
I doubt it but I’m wondering if this has anything to do with the filesystem, which is now XSF.