Seems right to me. The -3 number is whats allowing the computer to add the 3 degrees of timing to the base 18 degrees as long as knock, afr, timing, ect is inline.
Limit your car to 21-22 degrees of total timing for a fun street car on e85. It can be pushed harder but your tuning window gets very narrow. Looks like your tuner has you dialed in already. If you experience false knock issues save that for some of the existing threads.