Do all of the custom ROMs retain the "global capability" of Imagio?

[bigboy292000]

I unlocked my wife's Imagio and am lookin to flash it soon... but seeing that I'll be traveling to Beijing in few months, I'll be taking her phone with me (and get a local prepaid SIM while there). She can use my Vogue for two weeks.

So - my question is:

Are all custom ROMs here "compatible" with the whole switch from CDMA to GSM and choosing of another country? I think only one ROM explicitly mentions this in the first post...

I already unlocked the HSPL and I had Verizon unlock the SIM too.