I think that if things are bursting at the seams this is a good idea. But we’ve added Passkeys already, and the custom metadata ship has sailed. This is the kind of initiative I could see taking off as a solution to Passkeys, but it doesn’t represent a worthwhile investment for me now.
I’m at 1.6Mb, and with the frequency by which I update entries, the cost of data migration is relatively high compared to the data cost.