Hi Eric,
On your first issue, this is because the umask in the tapeserver is set to 0177. We use EOS for the repack files, and EOS has a non-POSIX behaviour, in that when a directory is created, the permissions are inherited from the parent directory rather than following the constraints in the umask. But when using NFS, the permissions follow the umask so you get 0600.
I will fix this in main by changing the umask to 0077. In the meantime you will have to work around it as you are doing, sorry!
On your second issue, note that releases with .0 at the end are catalogue update releases. That is, when you upgrade to that release, the CTA catalogue schema is upgraded but there are no code updates. You need to upgrade again to 5.10.1 or later in order to get the --isrepackvo option.
This two-step upgrade scheme is by design, to allow a smooth upgrade to a new catalogue schema across all tapeservers with no downtime.
Cheers,
Michael