Hi Pavel,
It should be possible to configure your fully mapped ignition to offer the same advance as the Rotax module and even incorporate the soft start timing.
The problem with microprocessor based designs in safety related applications is assuring the appropriate level of integrity. There are many ways of assuring this but having two identical microprocessor modules is probably not one of them due to the risk of common mode failures. Diverse design is the easiest method of achieving safety otherwise you have to employ certain software/hardware design techniques or extensive testing.
Kevin
