This an interesting thread, despite the head-butting between John C and Welder Dave. I've owned and operated a few graders - from old knuckle-buster Cat 12's, to hydraulic-over-mechanical 14E, to a full hydraulic 140G. And I've employed more than a few grader operators, some good, some not so good.
Plus, I've worked along grader operators who were highly skilled, and who could grade to a match-head thickness with knuckle-busters. Can't say I was ever that good, but I've built a lot of roads and banks that are still in use!
But in 30 years of being an earthmoving contractor directly, plus another 28 years of being associated with earthmoving equipment and construction and mining projects, I cannot ever recall - not even once - seeing any grader operator ever reverse the moldboard, and grade backwards with it in that position.
I'd imagine it would take a very versatile operator to operate effectively in reverse, and it would need an ability to develop a "reverse-skill set" to function as effectively in reverse, as going forward.
Having said that, I just happen to have a copy of the "Caterpillar No. 12 Auto Patrol" sales release brochure from July 1938.
In that brochure, Cat clearly state and illustrate the ability of the No. 12 Auto Patrol to blade in reverse.
However ... note that the No. 12 from 1938 had a moldboard length and wheel/tyre sizes that allowed for easy 360° rotation of the moldboard, without any fear of hitting a tyre or a step or any other part of the grader structure.
This is not the case with many later graders, and one has to exercise extreme care not to clip a tyre or step when rotating the moldboard.
I might add, I have never seen a grader operator working in a suit and tie, and wearing a smart fedora hat, either!
But I did have one dozer operator - who was a bit of a "character" - purchase a bowler hat and matching double-breasted English suit, from a secondhand clothes shop, and drive my D6C, wearing that outfit!
I must say it added some class to my operation, and brought a few laughs from clients!
One could also opine that reversing the moldboard was a more attractive option than trying to do a 180° turn, in an early Cat grader that didn't have power steering!
My first 12E didn't have any power steering, and I can still l remember the tricks involved in minimising steering effort, when it was time to turn around 180°!
And the never-forgotten lesson to keep your thumbs aligned with the steering wheel rim, and out of the spokes!