Nope.
Like
/duplicati-20240210T181146Z.dlist.zip.aes
And in the new bucket/backup they look like:
duplicati-20240210T181146Z.dlist.zip.aes
It even has weird consequences when downloading them from Backblaze. Single files will have the slash replaced with an underscore. Multiple are packed into a zip file which have the right size but show no files when being opened. Luckily extracting works and then the slash is stripped.
After work I will download my files and reupload them. Then try the backup again and hopefully upgrade.