Fueltech FT350 ECU Mapping

Hello. I have a doubt about tuning this kind of ECU, which is really basic. They don't have a 3D load vs RPM map. They have instead two 2D curves that overlap, one is Injection ms vs MAP, and the other one is a % correction vs RPM. Then the ecu calculates a "3D" map, but it can't be edited cell by cell. You can touch a row or a column. I think I should approach this by choosing an RPM value to move across load, and then deciding a load value to move across RPM. The question is which RPM and load values should I choose as reference for mapping. The car is a Suzuki Jimny with a turbocharged C16NE opel engine with forged internals, running on 98 octane pump gasoline. Thank you!