after "only" 18 hours of non-stop debugging, the setup is finally working as intended. FreeSWITCH segfaulting all over. I have serious doubts about how FreeSWITCH 1.10 could ever have worked properly with libpri-1.6.0 without my fixes.
also, various problems with the vintage laptops refusing to run this or tha combination of OS + terminal program in random order. In any case, setup is fully working now. Getting some sleep now, then preparing SIM card talk, then back to #36c3.