'Finally', as promised, here is the latest version of DOFIS, that now uses an asymmetric, split lens model.
This latest version gives the correct field of views (horizontally, vertically and diagonally) as the lens changes focus, ie fully modelling lens breathing.
It also 'correctly' estimates DoFs from macro to the deep far field, although DOFIS only reports relative DoFs greater than a mm

For the pano photographers, DOFIS now estimates the position of the pano pivot point, ie relative to the sensor.
The latest post and info on DOFIS may be read here:
http://photography.grayheron.net/2020/10/dofis-now-supports-macro-and-pano.html