Nerite Snails conclusion
After beginning my journey with my betta and nerites, I now have a tank divider in my ten gallon and a 3 gallon tank. My betta constantly would attack the tiger nerite. Never left his side, became quite aggressive with him, picking him off the glass. The first nerite was a black racer who hid all of the time. I didn't think my betta was aggressive with him, but caught him when he finally came out.
My betta was definitely almost non-stop flaring at the red tiger more than the black racer.
Separated them all and bought a very tiny (1/4") horned nerite. My betta flared at him on the 3rd day, swims close but leaves him alone. The horned nerite cleans the glass right in front of him. He'll swim close but then swim away.
I'm not an expert but for anyone wanting to add a nerite, I strongly suggest starting with a horned one. I was getting ready to give up on having one.
Hoping this helps someone on their betta journey.