^ Does a crashed ship with salvageable tech or quest artifact on the bottom of the ocean qualify for a "useful gameplay"? The one you can't reach without certain upgrade? Or progress your quest without? The one you can't scan to locate without a certain Magellan upgrade?
But then you're essentially again creating a thing where you create an entirely different tech, thta has literally a single purpose on a quest? I don't really have an issue if you gate entire planets away because of 'heat' or 'gas giants' or whatever. Because at least when you get 'magical macguffin tech a" you can go " oh yeah I can finally go to planet X now I hope there's some cool stuff!" where you're creating excitement for the exploration.
But to create a sub-per-planet gating system because you dont' have an upgrade is just annoying imho. You can create a problem where exploration is discouraged because of the constant back tracking when you get 'magical macguffin tech A', then oh 'magical maguffin tech B' makes you go back AGAIN, and so on and so on. You're not exploring something new, you're just re-hasing a place you've already been to.
Exploration isnt special. Its work. And each upgrade creates more work and more back tracking to a place you've already been to.