The ‘quad’ keyword always triggers my attention, as there’s still unfinished business regarding this issue: https://discourse.threejs.org/t/mapping-fidelity-in-quadrilateral-triangle-rendering/31033
The way I understand @prisoner849 's code is, that it is - while nice in its own right - only a very partial implementation of quad rendering. Because it uses a 2d context, doesn’t support hidden line removal nor bilinear texturing or even reflection mapping … 
@prisoner849 : Any plans, or even progress on that front in sight?