Advanced disk (or other type that uses @aaaab type of media id) is a pain as you suggest, as when rebuilding, unless the disk 'is' @aaaab ' (as only one disk on system) then yes, there is no guarantee that the disk is going to have the same media id. You can get around this - for exacple if the disk is @aaaac then if you added a temp adv disk first, that would be @aaaab, you ould then add teh disk containing the catalog which should then be @aaaac.
Ultimately though, you end up having to re-sync the dr file, you could edit this, but nbcatsync command should take care of it - which is the 'official' way, although I have seen issues in the past with it working perfectly.
The problem with putting the catalog to disk is getting a copy offsite, you could duplicate it if you have offsite storage.
The other problem with disk is thtat if the disk goes, or corrupts - you can lose everything ... Also Malware, I've seen customers lose 100% of catalog backups as the disks they were on were affected by the 'Encryption type' Malware attacks.
Sending the catalog to basic disk is the easiest way (you just recreate the disk with the same path) - ultimately, another copy going to tape is the ultimate protection, easily duplicated (should always have multiple copies) and easy to take offsite, protected from Malware ... Always be very sure to save the DR file offsite as well. The number of times we see catalog recovery needed with no DR file saved is unbelievable - no I can't tell you which tape it is on ...
I would not recommend putting the catalog on MSDP due to the extra complexity of having to get it all set up again.