I have the waterproof ones and wear oldschool 661 Rages under them- the big bulky ones like old Kyle Straits. There’s just barely enough room, and it does affect how they sit- it’s not restrictive exactly but over time they always basically fit themselves around the kneepads, rather than around my legs, if that makes sense? So that could be annoying if they come up short for you, as it could lift them up over shoes. Like most mtb trousers, they’re not long- which is bloody annoying tbh as there’s almost no downside to being a couple of inches longer, it just means they scrunch over shoes and give you a bit of room.
With a smaller pad I think they’d be absolutely fine, with my big pads they’re still fine but just not quite perfect. I’ve a set of Endura wateproofs and they’re very similar.
(on the plus side- I’ve found them all day comfy, never had a problem with waterproofness or lack of even though I machine wash them occasionally, they’re sturdy and well made. For me they’re only for really bad weather, not day to day kit, but every time i wear them I’m really glad for them)