With quirk like these, honestly I'm not even confident how can PostgreSQL or any software in general can be used in mission critical system.

Have you ever read the contraindication list of a medicine? It is the same kind of trade-off. Someone can choose to use something in a "mission critical system" (whatever that is) because the alternatives are worse, not because the chosen solution is perfect (that does not mean I would advise using PostgreSQL - just accepting that it can happen).

On the other hand "quirks like these" are the reason you should not update too often mission critical systems.

When you look hard enough it’s a miracle anything works at all.

Might be a bit late now to start telling people that maybe using software for everything wasn't a good idea.