for those that have tried to store UDF ISOs with rclone, you've probably realized you can't mount them in Linux using loopback mounting. To solve that problem I built a quick and dirty (about 2 hours) fuse fs in go with libudfread (which is not packages in most linux distributions).
should be fairly straight forward, will work on documentation later, now back to my real job.
one thing I should note: you should only use this when a normal kernel loopback mount is not available. It's performance is significantly worse the kernel loopback mounting.
also I now packaged up libudfread as a debian package and have a dockerfile that will build and export the static binary (without glibc net dependencies, so should work anywhere, fingers crossed), use build.sh. need a recent version of docker to do the export.