Add a module for perspective correction such as zPerspector for Aftershot Pro.
#4 Updated by Rick Gabriel over 7 years ago
zPerspector and others just offer a little more flexibility. For example, you can correct one corner of an image without affecting the others, you can bring a corner and one side in while leaving the rest alone, you can mirror an effect to the opposite part of an image, etc. The keystone correction and lensfun do account for the majority of corrections one would want to do, but it's possible to have some more flexibility here. I just wanted to get this into your system to keep it on the radar, but I agree it's very low priority.