Haven't looked into it enough, but logically, there is always a chance for addresses to diverge at least if Ethereum and Rootstock decided to do different things regarding post quantum accounts, even more likely if Rootstock takes the initiative first, then Ethereum won't conform then you get discrepancy. I support Rootstock taking liberties when necessary, I appreciate the compatibility, but when necessary to do a better job especially regarding supporting light clients and stateless clients and full validation, then if Ethereum isn't doing a good job, Rootstock should lead. But to be perfectly honest, Ethereum is doing much better job than people give it credit for.