I’m sure it’s probably great when you get used to it, but it scares me.

I have a start/stop button but never have used it. I wasn't sure how to use it. I bought my Janome used and the foot pedal wasn't working so took it back to the dealer where I bought it and he put a new foot pedal on and said it was under warranty-Yeah!!! Works like a charm now so you might want to consider replacing your foot pedal.

I have a start/stop button on mine but rarely use it. I always felt like I really didn't have control. But after reading some of your posts I may give it another try. It didn't occur to me to slow down the speed, especially when nearing the end of the seam. And I sometimes have trouble reaching my foot pedal due to being short and my foot pedal wandering. But maybe after a little practice I think the start/stop button might be the solution!

I use mine all the time as my feet can't stand the pressure on my feet as they were stomped by horses when I was young. I had to change from my Bernina to Babylock machines.

I have a Singer Quantum Stylus 9960 and I use the stop/start button all the time!

I use this function when using the fancy stitching, just because it keeps the machine at an even speed when adding decorative stitches to something, works good when adding the simple block font when making name tags.