I have heard
It is also good practice not to touch anything besides throttle and foot brakes when on the runway, I retract flaps only after clearing the runway.
before, but I do not universally agree with it.
I do not have experiance flyinf Barons, or Bonanzas (though test flying a Baron is in my future, so I'm oaying attention).
When I did my multi ride in a Cessna 310R back about 1983, I was nicked a point for raising the flaps just after touchdown. The examiner told me that one was not to touch anything while on the roll out. I pointed out to hime that the Flight Manual for the 310 (an aircraft with which I knew he was very familiar (it's why I had chosen him) specifically said for a short field landing, to raise the flaps immediatedly after touchdown. I had landed on a realtively short runway.
He did not disagree with me, and reassrted his "rule" as his preference.
I agree that while on the roll, it is unwise to perform un-necessary tasks, which if incorrectly accomplished have dramatic outcomes (and we know what they are). But one must still be able to manage "flying the plane" whatever that requires, so training to not touch anything is foolish...