Of course, the Parliament of the United Kingdom reserves the right to enact any legislation it likes, automatically overriding that enacted by any devolved body. It should do so as a matter of course. Anyone who objects should have voted against devolution, the legislation for which specifically states that this is the case. I bet they didn't.
Meanwhile, practically all Labour MPs from Scotland are now anti-devolution really. Many from Wales always were, and they now have a seriously sceptical Secretary of State to back them up. And even Lib Dems from the Highlands, the Islands, the Borders and Mid-Wales are extremely unlikely to vote more powers or more money to Edinburgh or to Cardiff. They have no more time for the amateur politicians (regardless of party) there than have Labour MPs.
So there would be no Labour or Lib Dem votes against such legislation on principle regardless of its specific content, and no Labour or Lib Dem votes (at least, not from off the payroll and from Scotland or Wales) in favour of further devolution in the unlikely event that any such Bill were ever even introduced.
There is the faint smell of a Nineties leftover, slowly decaying away to nothing like so many other half-forgotten aspects of the Blair Era, including Blair himself. Twenty years from now, will anyone even remember that there ever was a Scottish Parliament or a Welsh Assembly? Will anyone remember the latter even ten years from now?