As with many problems, you are never 100% sure it is fixed. You only get more and more confident over time until you forget about the problem.
About 2 weeks after my garage door fix, the door started bouncing up on fully closing. The immediate problem was how to securely close the door. I did this by timing my press of the remote to stop the door millimeters before the sensor would reverse.
I had to try and time pressing the button
This solution of course is a hack and an annoyance so I moved to do 2 things this morning.
1) I adjusted the spring tension on one side. By looking carefully at the bottom of the door when closed, I noticed one side was slightly (Maybe 1/2 inch) lower than the other side. I took 4 inches of cable out of that side… it’s a guess and may need a few iterations.
2) I adjusted the stopping sensor to stop maybe 1/2 inch sooner.
Now my opener uses a mechanism I’ve never seen before and not found on YouTube. It’s a black plastic thing plugged into the chain links. You adjust the stop point by moving it to another link.
Of course, I still am not sure this is the final fix and will only know with time.