Here is my take on it, after trying to use the steering brakes on my B8200HST. They work fine on my Farmall A, and on the Ford 8N I have driven.
I think Power Steering and 4WD have changed how steering brakes would be used and needed. Most more "modern" tractors have power steering. Some don't; my
B8200 is a late 80's
B2710 forerunner and PS was optional. Anyways, most have power steering, and tighter steering than the older 2WD tractors. Even without steering brakes, my
B8200 turns pretty dang tight; much tighter than my wide front Farmall of very similar size, and better than my Dad's old Ford 2N.
With 4WD, it throws a kink in things too. Steering brakes are effective in 2WD. But, in 4WD, you have a front tire that is tryin to drive. If you use the steering brake, you are kind of dragging the front around a bit; it does not work so well with that extra tire trying to get traction up there. I also think it is harder on the 4WD drivetrain if you try to use the steering brake.
I have tried on my B8200HST to make it work. Yes, it is hard to heel and toe the HST and the brake. I do not like the idea of the cruise control; if I am manuevering, I usually want to vary ground speed too.
Also, I have done it heel and toe, while trying 2WD vs 4WD. In my "test", it didn't work very well in 4wd... Spun her on a dime in 2wd, much like my Farmall, and the 8N I have driven.
I think the best answer is to let the power steering do the work.