What’s the problem with that? In my previous team, we had a structure with four levels of nesting where we only ever needed to query the first two levels. At first we used Postgres with normalized tables, but it was just slow as hell. Switching to MongoDB actually made our performance issues vanish.
Of course it all depends on what kinds of queries you need to run, but I don’t think that large JSON documents are necessarily a problem.
We have yet to see if they’ll stick to the Rust implementations for 26.04. If you’re running non-LTS Ubuntu in prod, that’s not on Canonical…
If we expect software like sudo to stick around for decades to come, a transition phase like this might very well be worth the investment.