HP-41CV and AME Port Extender Question

[rprosperi]

While not answering your core question, note that you cannot use X-Mem at all without an Extended Func/Mem module, in a 41CV.

And what is a "X-Mem Quad" module. 1 x Ext Func ROM + 2 x Extended Memory modules provides "full" extended memory, so it's not clear what a Quad X-Mem module is for?

Have you checked the ROM IDs for each of these modules? You can't have more than one module with a given ROM ID active (enabled on the Port Extender) at any one time.