Fitech ignition curve questions

I am not familiar with FiTech or any other OTS system. He are ideas that may help.
1. System setup is often done with help of conventional timing light, to set base timing reference so FiTech agrees with same timing value. That will answer question about dist vs crank, most likely crank.
2. Timing reference is advanced around 40 degrees, ECU following tables retards from there to generate actual spark timing.
I have no idea how your reference signal(s) function. That however is important.
A distributor cap is limited to about 40 degrees. Total timing can be higher, with base timing adding outside that.

2. Typically values for map advance 10 degrees max, so don't go crazy there. Might start with zero, so just RPM advance in table.

3. MSD ignition might generate enough electrical interference to mess with MAP, Temperature sensors, TPS, distributor sensing, ECU....

4. Monitoring and data logging of ignition trigger to MSD, injection signals, RPM, MAP .... with give immediate clues to why falling higher RPM.