I don’t really have an opinion on standalones, but this discussion seems to intersect with some other issues relating to, say, multiple builds on the same (linux) machine and the general path searching bonanza in sc.
I think something like a yaml config file, but including not just the class library but all or most of the paths relevant for sc is probably reasonable and feasible; like the current lang config file, there could be a scide gui option as well to pick out paths manually. Probably there could also be a portability/“standalone” helper that makes copies of all those directories within one directory, produces a config that links them, and zips the whole thing or something.
(It would be good to not have this rely exclusively on the scide, at least for scnvim users…)