IMO this illustrates that if a good lens is held steady [or image stabilization is used] much higher results should be obtainable in practice than your quoted 40 lppm.
Alan, Real photography is not shooting flat targets on a wall, not at all...
If you want to see the 120lp/mm film recorded detail on the print then you have to enlarge x20 or x40 to end in 6 or 3 lp/mm on the print, if you don't enlarge that then you won't see that detail.
At this say (x30) enlargement regular pictorial film does not offer much image quality anyway, instead if you enlarge (say) x10 to have image quality then you can see only 30 to 60 lp/mm of what recorded in the film.
Also it may be difficult to capture from the scene all what film can record...
Many subjects are mostly made of continuous shades of gray, still you may have edges in the scene, OK, but when we want project a dot on film that has 6 stops more exposure than another dot that lays 0.01mm far (50lp/mm) we have several problems... In a regular scene almost nothing is in perfect focus but in the Depth of Field, casting a circle of confusion for each dot. Also you may shot handheld, for example...
Then... what happens if you enlarge a lot and you take advantage of 75 lp/mm detail to be shown in the print ? It happens that you also show degradated contrast and noise ! When we downsize the print to not see the flaws then also we don't see the ultimate resolving power.
When we reach the frequency limit (80 or 127lp/mm) contrast is at extintion, near zero, this shows a detail that is it not worth to show in the picture. Still here YMMV, it is a personal choice WHAT image quality we want on the print.
Please check again this scanner comparison
https://www.largeformatphotography....Epson-Flatbed-Eversmart-Flatbed-Drum-Scanners.
The Epson delivers the same practical result (even if pixel peeping) than an Scanmate 11000 drum and two high end Creo:
https://www.largeformatphotography....rum-Scanners&p=1479178&viewfull=1#post1479178
The Creo is resolving 5100 dpi effective, twice what the Epson, but the Epson doesn't take a beating from a machine impressively superior:
https://www.largeformatphotography....rum-Scanners&p=1478451&viewfull=1#post1478451
The Epson resolves 55 lp/mm in the hor axis and 48lp/mm in the vertical one, but an scanner resolving just the double is not capable to show better results. Do you know why ? This is easy, the shot has not much more than what the Epson can take. And see how bad the image is when you show the 50lp/mm detail...
Still there are situations were you may craft a contrasty edge on film, if we have a powerful silhouette, in perfect focus, shot on tripod and at best aperture, but this is exceptional.
IMO, for all these resons, while we may cature way more, in practice we usually take advantage of those lower (say) 50 lp/mm, but not much beyond.