I don’t know if this idea could be transformed into some type of sticky but I imagine that there are a lot of users that have created expression maps or are needing one. It can be a time consuming task to create them. Sharing them with each other on the forum seems like a good idea. There are currently list posted here and there but updating web pages also takes time.
Personally I would love it if someone had an expression map for Session Horns Pro:
Expression Maps list by Steinberg:
Expression Maps list by Spitfire Audio: