Hi Mychaela,
My two cents on the subject is that any solution seems better than a fork. This is a small community, what we are doing is even more niche. Visibility is as important as the features themselves, therefor whatever the community thinks is appropriate to somehow integrate/merge these into existing Osmocom projects (MSC/MGW and libraries), seems like a better approach.
In this sense probably option 2. seems an easy way out of this for now.
I am also planning to add more Nokia BTSes to the supported list, namely Flexi EDGE, Multiradio and Multiradio 10. If anyone has access to a minimal viable setup (BTS+1 RF unit at least), or has equipment and can provide remote access, and/or want to donate it, please let me know. Of course older Nokia units (Talk family and even older units) are also welcome.
Regards, Csaba