Regarding lenses causing grain, please do your own test!
Use ONE roll and HP5+, Kentmere 400 Tri-X.
Develop in D-76,HC-110 or the worst for grain Rodinal.
No T-Max or Delta as they are too fine.
Shoot a few different scenes with older LEICA lenses.
Remove film and expose in any SLR, Spotmatic, Nikon or Canon.
Make 8x10 prints and compare.
The only "April Fool" are those believing I am wrong.
Erwin Puts came up with same conclusion.
Do the test!
The RFF is for sharing experiences and knowledge.
I shot thousands of rolls doing PJ, Fashion and Documentary.
PS I like grain!