I use the stabilizer bar or bars on the following:
3 pto hitch seed sower
Pond scoop if I am digging in reverse
Post hole digger..
I do not use the stabilizer bars on the plow, disc or spring tooth cultivator.
Always inspect your 3 pt hitch connections, my friend had a lower lift arm break while Bush hogging, the Bush hog was being lifted up the rear tire but he got the tractor stopped before he got hurt. However the rear tire was shredded.