If your text is printed inside the object, then it has to switch the filament for every layer, retracting the filament, switching, pushing and so on. As far as I can see, it’s not possible with external spools because the AMS has those motors that can move the filament back and forth. I think it’s possible with custom g-code and only external spools (no AMS) but then you have to manually switch filaments so many times…
If your text is printed outside the object, basically a text on top of a base, I don’t see why do you need AMS for that. Put a pause in the slicer when the base ends and the text starts. Print with one filament, manually change it to the other one, resume the print process. Another idea is to print them separately and glue them together.
But as others said, use the AMS, only take care of the nozzle.