Content warning: tedious programmerese. Viewer discretion is advised.
Welp... making this fast enough to be usable on macOS was a massive two-day refactoring effort resulting in a model-view-adapter class set and the destruction of a large plate of spaghetti code. Will probably be another couple days before the result of this hits the nighlies, but once it does it should be nice and snappy. This also fixes a couple quirks having to do with column size and dialog resizing, by switching from the buggy-as-hell wxTreeListCtrl to the much nicer wxDataViewCtrl.
After this is complete some modifications will be done to address user feedback, and then footprint selection and 3D preview will finally be implemented.