Roger Williams

By which I mean, which functions can recognize an equirectangular image for a 360 x 180 degree panorama and ensure that the two sides of the image that will form the seam are given similar treatment so that there is no obvious seam viewing the entire VR image? Or perhaps I should phrase it the other way around: are there any functions that will often make seams visible because they do NOT try to equalize processes on both sides of the seam?

I have just bought Affinity Photo and it certainly looks very impressive. Unfortunately I cannot find the function for which I bought it, nor can I find references in the FAQ and Help links. I wish to edit equirectangular panorama images (the standard 2:1 aspect ratio files that cover the entire 360 x 180 degree sphere). I do not wish to create panoramas, although I see that Affinity Photo offers that capability, at least for cylindrical panoramas. I want to edit images that I have either stitched myself from multiple exposures or taken on the Theta S panorama camera. Help!