I looked through everything I could find online (see links at the bottom), concluding:
Most important: People mixing Somfy RTS with (Somfy originating) io-homecontrol.com - They are not the same!
To the best of my knowledge there is currently no implementation (which is not using cloud based Somfy Tahoma, or is soldering a remote)
There is a setup Device called somfy set&go, which some guys startet to reverse engineer the communication, without success until the end of 2015
The chips supporting io-homecontrol available (e.g. ADF7022) reveal no details about the communication protocol
IMHO there are only a couple of options at the moment:
Continue to reverse engineer the Set&Go communication (See point three above)
Buy a ADF7022 evaluation board (hope that they deliver the full datasheets too), try to reverse engineer the Somfy Protocol OSI 4 to 7 with it and implement a driver (this would probably be the most sustainable option) - I think there might as well be a way to officially gain the encryption (AES or 3DES) keys, since they are exchanged at some point in time concerning to this [page 3]
Crowd-source some money and let someone do it for the public domain
Reverse-Engineer the whole thing (all OSI layers) with an SDR and see where this gets us (e.g. like him or him2)