There was a bloke who worked on a farm next door who used to keep a pair of slippers in the cab, and always took his boots off before he got off the top step!
We do the same in the forestry machines except just socks (no slippers) since we have really thick rya rugs in them, does wonders for the perceived comfiness in the cab. (If you've never tried it you are missing out! )
And if we ever do find a newer tractor for the right price that would be the first customisation done to it...
Indeed, for some forms of driving, particularly rallying, left foot braking is very very useful.
Nigh on required even, as there are some cases where you want to brake and then apply throttle with as little delay between the two as possible.