FWIW we add a lot of new features, but we break very few APIs. API stability is extremely important to us, so you can actually build stable things on Docker and trust that we won't break it down the road.
As far as start/create params, these should not be changed at all, other than that you can pass the options that you could one only pass on start to create. If something has broken here, it was most likely a mistake and should be reported on GH. Even if we change the underlying configuration, we do version the API and make sure we are sending/receiving the same structs over the wire.
TLDR; if something broke in the API, please report.