Gospel truth. Amazing that the thread got this far before it was brought up. A couple % torque, or as little as a 4 or 5 knot airpseed change will demand rudder trim. It's simply a fourth primary flight control, treat it as such and budget your workload so that you have a hand to run it.

Disclaimer: I haven't turned a prop on the Brasilia for 2.5 busy years so take everything with a grain of salt.