You should consider donating to it's OSS competitors. Still lots of catching up needed in the cad space.
Maybe Assembly, but I can always download the Assembly3 plugin.
Outside of having to download a plugin, FreeCAD has never limited me.
Using the Solvespace solver is an interesting problem: it would switch up the FreeCAD licence from the LGPL to the GPLv3. The FreeCAD folks don't want to do that: it's fine from a licensing point of view, but they don't want the additional constraints.