Since I always "start" my machines, no matter which one I'm using, (the way my mama taught me...it's habit whether they need to be started or not) the only time I had trouble treadling was with my Singer W9...because the handwheel is backwards to most machines. Instead of pulling it toward you to start the machine, you push it away...
Other than that, I can't think of any problems I had with treadling...it was the same to me as an e-machine with the exception of I get to move my feet instead of having to hold one on the e-machine's footfeed or hold a knee to the kneebar...I tend to have restless legs so treadling fits right in!
The only problems I've had is when I did some FMQ on my 115....and my problem was a lack of stamina!
Most quilting are short seams...FMQ can be one very long "seam", and my legs wore out!
I treadle with both feet, heel of right foot on the far side of the pedal, toe of left foot on the close side...