A landscape shot at F1.2 won't be much of a landscape will it, sorry your post is BS
If your focus distance is so far (landscape), does it matter if you are shooting wide open other than you are letting in more light?
I am not sure if you understand how narrow a DOF you will have with a 1.2 lens.
There are very few lenses that have that large of a maximim apeture as large as 1.2 to begin with.
I own a 35mm 1.4L and even that lens wide open has a razor thin DOF.
A common landscape shot wide open with it usually would be a bad capture.
The exception is if you are really trying to isolate something specific in the shot. For example a lighthouse, leaving pretty much everything else out of focus.
A shot like that would usually be better showing the ocean and rocks, or whatever is around it for the full effect.