We have a L4610 cab which is very small, and places are limited for mounting. We customized our own mirrors by cutting our mirrors to size and mounting them in sheet metal frame. Small, maybe 2-1/2"x4" in each outer corner and maybe 3x24 across the center. Because of the small cab, they are fairly close to operator, which makes view clear & larger. We seldom have to turn to look to the rear. but mine are not set to look a long distance to the rear.
We watch the rear of our 7' finish mower & can back up to any object & touch it without HITTING it, or skinning the bark on a tree.
Working with grapple on loader, we can back up to most anything without having to turn around. When working disaster relief, we really concern a lot of people when they see me looking forward while backing up close to something like a car or building. We also use the side mirrors, but we have to move our head more for the side mirrors, than the inside cab mirrors. Only have to move eyeballs for them.