Wow, very surprised to learn that it is closed source, and that's probably not changing.
My local mesh was testing out meshcore last week, this definitely kills my interest too
Shame to hear that: the protocol works well, scaling up to thousands of nodes across hundreds of miles. This is the local mesh where I live: https://cascadiamesh.org/map/
You don't have to use the closed source app; there's an open-source client too, there are Blackberry-style client devices which don't require an app at all, and all the actual firmware is open source (MIT).
This reduced my interest to zero in this as well, when I learned it was closed source
Thankfully there is an open-source client, which has pretty much all the features of the main client as well as some extras.
https://github.com/zjs81/meshcore-open