Hi Morten,
there’s recently been some action going on Somfy io devices:
- [velux] New OpenHAB2 binding - feedback welcome! - #236 by gs4711
- Control Somfy io or Velux windows with KLF 200 and HTTP binding (the solution I have applied and which is working so far flawlessly)
Perhaps it’s of some help for your case, if you want to drop the Tahoma box (for me it was a privacy concern to have all in their cloud).