DPFs don't work satisfactorily with bio and I had very vague recollections of a few cars monitoring exhaust gas components, but I can't find any reference to it now. If it's true they will see different levels of gases and most likely go into limp home mode.
Not exactly my area of excellence I'm afraid.
There aren't really any issues running most diesels on bio, providing it's well made. There are occasional reports of IP seals going but it's hard to say if that's the result of bio or just ware and tear. Most common problem I've heard of is disintegrated spill back pipes. My own experience on the Disco was that the spill back pipes certainly looked like they softened to the point of disintegration, but no such troubles with any other pipe work.
B50 probably won't prevent such a problem occurring, just delay it, so if you are going to the trouble of making bio, grab the full financial advantage and go for B100.
What car are you proposing to use the bio in?
