i found with gigastructure's if you convert those to giga colony gas giants they give special features.
that or trow down a habitat ontop of it, habitats can mine allot of features with guili's if you decision build them. they also work to improve rare resource deposits like nanites, but colonization of said hab is required. some are passive deposit but much bigger then default.
and yea that generated deposits checks space mining yields before it makes it.