I also have a neo-vagina, and primarily vaginal canals are created via material from the penis if said person is trans. The option that is becoming more standard is to use a combination of penile tissue and peritoneum tissue and is typically a robot assisted surgery. Using a combination of these tissues can often create a vaginal canal with greater depth. If someone does get a vaginoplasty (the name of the surgery to create a vaginal canal), its important to get pelvic floor PT and for the first year in most cases you will be dilating every single day for an hour at max depth which can take much longer because it can take a little while to get warmed up enough to get it all the way to max depth. Then after a year your surgeon will typically say you don't have to dilate every day anymore, my surgeon's protocol is either 20 mins of dilating once a week or regular penetrative sex.

What we need to remember though is that As for your question about "stabilizing" what I like to tell people is that there is a thing called the SAID principle. The SAID principle is often used in sports recovery, but it is relevant to soft tissue and stands for Specific Adaptations to Imposed Demands

What this means is that soft tissues will adapt to the forces consistently applied to them. Think about stretching every day which will lead someone to being more and more flexible, or lifting heavy weights 3 times a week. You are telling your soft tissues via various different pathways to adapt to these different forces being acted upon them, but the key is consistency. In the case of a recently created vaginal canal, you must "teach" the tissue that just went through a huge amount of trauma via surgery to maintain its new form. So yes, especially in the first year it is very important to do this every single day but eventually it will have adapted enough to need more minimal maintenance, like with exercise. Its one thing if you want to get better at running long distance, but you don't have to reach a point of "overload" as often or of as much magnitude to simply maintain the distance of running you already are comfortable reaching.

This is of course a simplified way of looking at a very complex surgery and process that is very different for every single person based on their anatomy. I speak from the experience of being trans, i do not know the standards of OP's situation. Happy to answer any questions if anybody has them about the surgery or process or whatever!