In terms of physical size he and Stills are practically clones and Stills played on the inside the majority of last season.
It's not his size that concerns me. It's his ability. Nothing he has done inside says he is worth a 1st round pick to play that position. I've gone back and watched his 21 and 22 film when he played much more inside and it's extremely meh.
If he's going to line up on the Edge 70% of the time he plays and 30% inside depending on the down and distance then ok. I still think he should be a full time edge because everything that made him a 1st round pick came from the Edge, but I can live with 70/30.
If he's going to be 70% inside and 30% Edge then it's a huge waste of a pick from what I have seen. As a DT / 3-4DE you could have gone all the way back to pick 54 and Michael Hall and got a better interior lineman.
Before last season started, when he'd played predominantly inside, he was a projected day 3 pick. Literally everything that made him a day 1 pick came from him playing Edge.
I've heard the poor man's JJ Watt comparisons with the ability to move in and out. JJ only played 12% of his career snaps at 3 tech. He played most 44.4% at 6 to 9 tech, wide Edge. And 42.9% at 4/5 tech. So over 87% no further inside than head on with the tackle. If that's how me use Robinson it should be ok.
At the Eagles Gannon liked to play Okie fronts with someone inside at 4 tech directly over the tackle and someone with speed on a wide alignment they would be forced to block with a TE. That would be ok in true passing scenarios.