On the Trike the rear brakes are much more important in a hard braking situation than on a 2 wheeler. Even if you had ABS and the front tire did not lock up, it is not enough braking power for emergency braking.
I, too, have a bad right ankle/foot, and found that, for me, an extended and lowered brake lever makes it much easier on my ankle to use the rear brakes. Don't know if it will do the trick for you, might be worth looking at, at this
LINK.
Installed on my TG-
If you don't already, a
Comfort Lift Kit™ will put a little more weight on the front tire, giving it a bit more traction, still not enough in a hard braking scenario to not need the rear brakes also, but every little bit helps.
Another thing that will give a bit more traction to front wheel braking...next time you need a front tire, go with the Avon Trike Tire, it is grippier.
Kevin