As a data point. I took out the rimfire G19 Glock trainer and ran a couple hundred rounds through it and set my own personal record on the Supertest raising it from 282 to 288. I then followed with shooting a 9mm G34, and duplicated the Supertest PR at 288 on my first run. Results then deteriorated as I shot the 9mm more.
I think there is something to this rimfire thing as far as trigger managment and learning to not flinch the trigger.