Jorge Castañeda
Leo,
Try with the tool rest even higher, say 1/2" above center-line and you will be surprised how easy many things become.
After much experimenting with edge shapes and angles, I am back to straight edges, with no concavities or even slightly convex.
Somewhere I have a rounded edge skew I use occasionally as a scraper on the inside of bowls.
The other thing, they must be surgically sharp, if they are not you will be very frustrated.