Why is the internal travel adjustment for elevator / aileron / collective pitch set to 110, 110, 90 by default?
These are optimised values based on experience in various tests with a variety of models and linkage types (carried out by robbe). They are designed to ensure that the unit can directly accept the standard unmixed transmitter settings in as many cases as possible. In any case, it is straightforward to modify these settings to suit particular models, either at the transmitter or using the PC adaptor.