Well designed batteries can be slung so that if they catch fire they can detach from the aircraft and fall on someone below. Anyhow a lot of commercial aircraft have been using NiCad which can suffer thermal runaway for years. They have a protection circuit to prevent overheat. As said before wading through tons of kerosene is far more dangerous following a crash than flash battery fires. Almost all cabin fires are from batteries that have been tampered with or broken/crushed, so have been compromised in their own thermal protection, which is why now they say to leave dropped phones and wait for an FA to come and search for it, lest you crush it and cause a fire.
In anycase first trial flights are supposed to be in under 2 years, so we will see soon if its realistic or not. In regard to SAAB and the TC, they will explore anything and help with certification, for a fee, lots of modifications have been done to SAABs, including airframe modifications and so on. Pretty sure SAAB would be heavily involved from a consulting point of view, you just have to read SAABs site regarding regional aircraft where they advertise how they will provide technical assistance for operators.