strawbo13 • Adobe Employee, Nov 07, 2019Nov 07, 2019
This feature has been implemented in Photoshop 2020 (version 21.0). You can have a grid with any number of grid points, and you can place custom grid points anywhere. You can also multi-select grid points and transform them together.
As far as I can tell no one asked for the 90˚-angle-locking of the bezier handles of non-corner points so the attempted implementation seems like an obvious failure and I think the »Implemented«-marking of the Feature Request should be reverted.