IF already incorporates elevator trim and I think that IF should at least add on of the two flight controls listed below. It would allow more control of the aircraft and a more realistic experience.
Rudder Trim - It is especially useful with high crosswinds when landing and taking off. As for smaller single engined aircraft especially powerful ones such as the TBM-930 they require rudder trim to offset the “left-turning tendency” caused by P factor and propeller wash hitting the rudder.
Aileron Trim - It is equipped on the majority of all planes however it is not used every flight. In fact most pilots don’t touch it. The main use for aileron trim is if there is a fuel imbalance or when an engine failure occurs as it can help balance out the load.