While I agree that it is only sensible to expand on the SpaceNam line (and maybe produce WGA’s first vehicle set?) – after all most games do require more than just basic infantry – my personal preference is more in the realm of Historical and Fantasy-Miniatures.
So something like an upgrade sprue adding the more fantastical elements of the RO Mercenaries & Militia set to the WGA Conquistadors would be lovely. Together with a second sprue offering the SciFi elements this would massively expand the options of an already great set while hopefully not taking up too much space in the casting moulds.
But tbh all of the RO stuff is great and will make quite a number of people very happy.