Here is the simulator I used for DoF/CoC/print size evaluation:
Advanced Depth Of Field (DoF) Calculator | PhotoPills
CoC = 0.014 (14um) = f/14 (hairy disk ~14um) => print size A1 at 15" viewing distance.
Now if we decrease pixel pitch (more mega pixels, same sensor size), we need to open the lens aperture to reduce diffraction and reduce CoC in order to print larger, but then the lens FL should also be reduce to increase DoF. Benefit from more Mega pixels without TS lens means using a wider lens. Now, if we keep the same pixel pitch (more mega pixels, larger sensor), we need to stop down the lens to keep the same DoF, which also increases diffraction. So again, to benefit from larger sensor with more MPixel, without TS lens, we need to shoot with wider lens.
Conclusion: the only way to benefit from more than 50Mpixel and print larger without TS lens (or without focus stacking), is to use a wider lens.
For full frame, the sweep spot of print enlargement, without TS lens, without focus stacking, is with 20mm lens. Basically, the solution is a 20mm prime lens mounted on Sony A7RIV.
---------- Post added 07-07-21 at 10:24 ----------
Originally posted by AfterPentax Mark II I never look at the corner of a picture, I always look at the subject.
That is true of subject in focus, background/foreground OOF type of photographs, and in that case, enlargement potential increases significantly due the ratio of local pixel count to subject detail. I have printed 48 inches of a carved stone statue, from a Pentax K1 file, shot handheld in low light with SR, sharpened with Topaz AI. Even looking up close I can't see any lack of sharpness or pixels. In my architectural prints however, I can see lens corners are clearly a limitation, I could print a lot larger if I used a prime lens.