Is testmasters worth it if I already got a 1910?

Si I’m hoping to bump my score to about a 2200+. I heard that once you hit the 1900 range the only way to increase your score is by self-studying and that these courses were designed for people who score in the 1200-1700 mark. Is it really designed for slower kids?

I got a 196 on the PSAT last year. This year I started a course with PrepScholar and I am already getting a 2100 on the SAT. So, they help.