I don't know of anyone who specifically supports the 545 RFE transmission. I do know that the makers of Megasquirt a DIY ECM for fuel injection also make a DIY transmission controller.
No one has yet used one to control a 545 although there is a guy in the process of getting one to work behind a 47RE. I do not know if the transmissions are similar, but at least it may help get you started.
