I tested the metronome thing with a vibrating metronome watch and I can say that it does help with my stuttering. The vibrations makes your brain think you are speaking in a rythm, which helps a lot with blocks. I bought a cheap at ebay, is easy to find. It is a great idea for phone calls or online meetings. Maybe try it using character.ai, the app where you talk with famous characters. For in person, maybe a more expensive and quiet watch would be better. You can hear the vibration. Maybe with ear metronome? I keep you guys updated after more testing.