Literally any wizard with AV and the knowledge of how to make a powerstone can turn it into a liminal realm. Why are you so certain that secret lore that only Mathilde can get is a necessary component of how to make it? We made the liminal realm. The problem was that there was a demon nearby who took advantage of the opportunity to talk to us. It is not an inherently demon-attracting activity, and "how to ward off demons" is not a thing wizards need secret lore to do. It is a well-studied topic!
It would make our AV book less impressive to not have made a liminal realm without an evil bird showing up, but other researchers could definitely take it from here if we chose to spend our time on other things.
We're the only person who can check to find out if making a liminal realm automatically or frequently attracts greater daemons without having to try it. Otherwise the greater daemons could be doing things like lulling wizards into a false sense of security by allowing them to make unprotected liminal realms and not attacking for the first few years.
We can talk to the Eonir about that, as it's relevant to the Waystone project, and we can ask Gunnars, as Gazul may have done something we know worked, and he may be able to give some hints.
We don't actually know if the current method of creating liminal realms is inherently daemon attracting. We have a sample size of one. It may be, and we may need to add something to the process to reinforce the walls of the liminal realm or similar. What we do know is that our current method of making liminal realms produces realms with weaker walls than regular reality. We don't know if that's inevitable, or, I think, to what degree they're weaker.
Mathilde is uniquely capable of investigating if this is a problem and if it is what methods need to be taken to address it, as she can talk to people who know in a way no one else can. Maybe they'll say that it always attracts greater daemons and you need to be big enough and bad enough to kick them in the face and throw them right back out so you can then build anti-daemon wards, and we can know and act accordingly. Maybe they say it's bad luck. Maybe they say that it is vulnerable to Aethyric entities, so you need to dedicate to one, such as the spirit of a piece of geography or a deity. Maybe you need to put a twist in as you push the AV out of reality.
We don't know, but they probably do.