So.. in 1.0 (and according to the UFOPaedia), crafts need a map block of type 1 (= Landing Zone).
In the new version, according to Falko in the FMP thread, you need a map with "group: 1" instead. I'm not sure if that's the only thing that is required though.
Do the nightlies still use the "type" property? If not, leaving it there for v1.0 / older nightlies to use could allow both to exist.
As far as I know, v1.0 / older nightlies don't use the new stuff (groups and whatever else) and would just ignore the new properties. As long as the newer nightlies also ignore the "type" property, you can define both in the same ruleset without conflicts.
That would allow the definition of crafts that work both in the release version and in the new nightly maps. Or is the new implementation of crafts intrinsically incompatible with the old implementation of crafts, because it uses the same property with different values?