Hey guys, I've recently reverted back to the default UI (trying to cut down my dependence on addons) so I can't actually test this myself.
But a POSSIBLE "fix" for Grid2 might just be to update the whole thing and change RealUI's settings so it doesn't manage Grid2's layout. If you can completely change and add profiles as normal I can't imagine why you can't just disable management of Grid2 and keep it updated yourself, albeit maybe having to recustomize some of the aesthetics yourself if you really want it to match. The auto layout centering and sizing might be gone though unless you manually swap different group-size profiles.
Worth a shot imo but like I said I'm trying to stop using addons almost entirely so obviously I can't tell you how well this works unless the very likely scenario where I can't live without RealUI comes up.
Does anybody know what exactly was changed in the bundled Grid2 main module so we can maybe just keep manually updating Grid2 and re-applying said changes?