I was able to fix my low-speed brake squeal issue very simply.
After a few hundred miles on the T120, my front brake squealed badly. I used anti-squeal grease, which seemed to help for a bit, but the problem returned. The *third* time I did this, I used sandpaper on the pad face and chamfered the edges of the brake pads (old Volvo trick) and the brake squeal soon returned.
I decided to approach this from a different angle. Maybe my technique was at fault. My previous 2 bikes were BMW’s with linked brakes and I developed the bad habit of never using the rear brake pedal except in an emergency situation.
Once I started using the rear brake petal in conjunction with the front brakes, the problem completely disappeared. I have >1,500 miles since the last squeal.
Try changing your technique, it worked for me