I haven't used them before, but I can anticipate some issues, like getting them to line up with the on-screen dial, and how to deal with knobs that are "pegged". (Both pretty minor.)
The bigger question might be about what to do when the users get spoiled and want physical representations of graphical controls for ALL the front panel objects? 😄
(Mid-Level minion.) My support system ensures that I don't look totally incompetent. Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all. Humble author of the CLAD Nugget.