Lens shifting View FoV vs Camera FoV difference

When lens shifting to stitch a grid of subrenders together into a full render, the images stitch together fine, however when compared with the full render of the same size, the edges of the view are viewed from a slightly different perspective. This comes from the fact that the camera FoV (FoV attribute of the lens) is using the same value as the view FoV (the view angle of the canvas).

If these could be decoupled to lock the camera FoV, then change the view FoV and lens shift separately, then this would allow for seamless renders to be stitched of different canvas sizes, and not have distortion if rendered with multiple smaller renders compared to a single larger render.