I used to keep a little down trim in the elevator to keep a little pressure on the stick in level flight, which allegedly kept the model flat when exiting from loops, and to reduce the amount of push when inverted.

But now I use neutral elevator. I figured out that if the plane was ballooning it was because either the plane wasn't set up properly or I wasn't relaxing the stick at the proper time. And I adjust CG so that inverted push is minimal, and put the fuel tank on CG to reduce elevatortrim changes.

I use (to a certain extent) the technique you mention to turn the Decathlon. I initiate a bank with the ailerons, but use only rudder and perhaps a bit of opposite aileron to keep the wings at the desired bank angle. With the amount of differential I have dialed in, the plane needs no elevator to maintain altitude.

Because of its large amount of fuselage side area, the Decathlon requires only a breath of rudder for knife edge, but a ton of opposite aileron.