Burns oil when cold

It’s more likely the piston rings. If it was valve seals you would see smoke right at start up, because the oil leaks off the heads and through the seats after shut down. Which leaves oil in the chambers for start up. Typically smoke from a valve seal leaks goes away as the engine warms up. You also don’t see much oil loss from valve seal leaks, since it’s an intermittent oil to the top anyway.

Weak rings, on the other hand, wouldn’t leak immediately on start up because there isn’t a ton of oil being thrown around and nothing in the chambers to start. But as you get going the oil pressure rises, oil gets slung around more and the load on the engine pushes it past the rings. Then as the engine gets up to temp the rings expand a bit and reduce the leakage. At that kind of mileage I’d expect the rings to be pretty tired.

The smoke after turning would indicate rings too, you turn, slosh the oil in the pan to on side and up the walls, and the rings can’t seal it out of the cylinders.