OTOH, a PS pump with 270k miles on it can’t be good much longer, I would think, even with no flakes...?
Understood but it is an inexpensive first step in dealing with what can be a messy, difficult to get at repair.
https://www.lucasoil.com/product/power-steering-stop-leak/
You can also get PS overhaul kits, and don't forget the salvage yards.