its not the most elegant nomenclature, but the stuff you’re looking for is in CroneAudioContext:
one of these is assigned to the context variable of the CroneEngine superclass.
so you use context.out_b for output and context.in_b for input.
note this oddity: context.in_b is an array of two mono busses. context.out_b is a single stereo bus. (this just seemed to match closer to most of the use cases. in_b indices are adjacent so you can treat them as a stereo bus if desired.)
also: context.ig is a Group conteaining input synths, context.og is a Group with output synths, and context.xg is a Group between them for your use.
(ha, i even left a FIXME in there to make the names less stupid. it is probably not quite too late to change them? no, it’s probably too late.)