Skiff I admit I was wrong in my previous posts confusing CMS with HR-50, etc.. but those 800 lp have to be brought onto the paper and you can't really do that the paper doesn't have the resolution neither does the lens btw.
That is the wrong idea how resolution in an imaging chain works.
It works this way:
1/system resolution = 1/lens resolution + 1/ film resolution.
The higher the film resolution, the higher also your system resolution (final/end resolution).
That is by the way also the reason why you get higher resolution (an improvement in resolution compared to conventional films) with CMS 20 II even with mediocre lenses.
Close down more than 4.5 and most lenses even very good one will be outresolved by the film.
With this film you can reach the physical limits of lens resolution: the diffraction limit.
Zeiss has done that and published the results with its 25mm ZM Biogon some years ago: 400 lp/mm at f4 with this film.
You will find further test results here (post 19):
https://www.photrio.com/forum/threads/rollei-rpx-25-grain-and-resolution.115244/
I have tested some of my 50mm standard lenses with CMS 20 II at the best aperture 5.6 and also reached the diffraction limit for white light (250 lp/mm).
So those 800 are a nice marketing gag but nothing else.
Completely wrong!! You need this extremely high resolution of the film to fully exploit the lens resolution and reach the diffraction limit of the lens at the optimal aperture. See formula above.
Also it's interesting that you and Argentia keep comparing it to FP4 which is very far from a modern film.
I cannot speak for Argentia, but I have choosen it because it is the most popular medium speed BW film.
I've also done tests with Delta 100, Acros, TMX. With these films there is in several cases a small advantage for 35mm CMS 20 II compared to medium format T-grain film (4,5x6), in one case a minimal advantage for MF (6x7 with Mamiya II and Delta 100 and TMX).
Also isn't HR-50 based on a film that was not made by Adox (say Aviphot 40 or 80) but bought by Adox who applied their "speed boost" technology (which many believe to be just a fancy word for pre-flashing). If indeed the film is based on aviphot those 800 lines are only possible at an object contrast of 1000:1 = 400 line pairs or 800 dots/mm.
1. You are again mixing the two films up: CMS 20 II and HR-50 are completely different films.
2. The resolution function is not linear from medium contrast up. So the resolution difference between 1000:1 (10 stops) and 32:1 (5 stops) is minimal and not field relevant.
Zeiss made their resolution record (see above) also at a quite low object contrast of about 4 stops.
Your comments here demonstrate that you never had proper resolution tests done by yourself.