Well I've reviewed what exactly I want out of Foxblade, and have been doing a survey of all the major engines. I gave Godot a spin, fiddled with Unreal, opened Unity and felt an immediate wave of dread before promptly closing it again, and even gave Electron+PixiJS+WebGL a shot.

At which point I exclaimed to myself "Fuck this, I will just write it in FNA and it will be fine."