something just jumped out at me in your post. and again your location may go by different standards because you are in a completely different country...

you stated ...

here in America dissociative type alters are more active when there is more triggering/more stress\ more instability...

let me show you what I mean...

when i was stable, not triggered and able to take care of myself and my life...

for example (all my medications for bipolar, depression anxiety,...were working, when I wasnt having any dissociative symptoms (feeling numb, spaced out, disconnected) when I wasnt triggered by something that I could not handle (nothing in my life was causing me emotional turmoil, nothing in my life was causing me to dissociate, I could handle all my problems on my own)

there was no need to dissociate, no need to switch into alters because my life was on track, non triggering, non stressful and stable...there was no need for the alters to take control to do their job, purpose, reasons for being created (in other words their sense of agency)

this kind of thing has been documented with mental health treatment providers treating DID, here in america so much so that the diagnostic criteria now includes that there must be these components of how and when alters can take control, how much control they have when they are in control of the body, what their jobs, purposes, reasons for being created are (in other words their sense of agency which you can read about in my links at the bottom of my post)

my point...if you were here in the USA, your alters not being active points towards a good thing because it shows you have more stability, better coping tools to where you are able to handle your life with out the alters taking control to do their jobs, purposes, reasons for being created. it was also in me pointed to the alters integrating/merging\ becoming one with me because they were no longer needed.

since your alters were active years ago and now are not active my suggestion is to look at your life. see how stable you are, continue to use your treatment plans that have enabled you to be more stable so that the alters felt they no longer had to take control, no longer had to talk\supply information. maybe its already with in you to discover what ever is lurknig under the surface without the alters help.

again since you are in a different country it might be best for you to tell your treatment provider what you are feeling so that they can explain to you what dissociation is in your location and what alters going quiet for years means in your location and what diagnostic criteria your location uses to define what alters with dissociative disorders are, can do and such things that may reflect into what is going on in you. your treatment provider can also let you know whether what you would like to do (guided imagery for communication with alternate personalities) is legal and ethical in your location.

i know that you are afraid to talk with your treatment provider about having alters but sometimes it can be really helpful, who knows maybe your treatment provider will have some treatment options that will help you with out it going against the laws and ethics in your location.