Definitely not an expert on it, but like you, have read some things to try to get an understanding. Agree that it isn't necessarily high spin rate, it is a spin rate that is higher or lower than average. Basically making the ball move differently than anticipated due to the way an average fastball typically moves. I started looking at it before my son committed. We were at a Vanderbilt camp and my son and another kid had basically the same velo. Both boys were asked to stay after and tour the facilities. After the camp, they sent us all the trackman data from their 3 minutes outing, but it also included everyone else in the spreadsheet. My son's spinrate was higher than average, the other kid's spinrate much lower than average. They committed the other kid a few days later. They called my son for months but never offered. The other kid was pretty small compared to mine so I always thought it had to do with spinrate, as they were both equally effective in their outings.
My son has never thrown a 2 seam either, but is not an over the top pitcher. For the 26.6 Bauer Units on my son's fb: 93.5 SR: 2484 IVM 14.9 IHM 19.6