sort of. some people perceive as in feelings that their system as laying dormant, but dissociative type alters are a very special kind of alters.

example my alter red, her sense of agency was anger. as long as I did not encounter a trigger that caused the emotion of anger red did not take control. to me it may seem like the alter is laying dormant inactive when its actually me not encountering the trigger that caused me to dissociate into that alter. I also did not have co consciousness with all my alters so who's to say that when Rainy was in control nothing made her feel angry which in turn caused a switch into red. see what I mean on my side it may have seemed like an alter was domant when in actuality that alter was still on the job doing what its sense of agency is.

is this different than having a new alter in my location, yes.

I know you like to figure out the ins and outs of everything so a suggestion ...to figure out the differences and such you will need to contact your own treatment providers. they will be able to help you figure out what kind of system you have and whether you have what my location calls new alters vs perceived as dormant alters, and how that fits in with the new diagnostics and definitions of sense of agency that each alter and those they reside with in have. this kind of in depth information isnt on the internet.