Well, I guess technically anything's possible, but to set up a 40 size trainer for 3D (as an example), you'd have to put say a 91 two stroke in it, remove all the dihedral (and probably remove a couple of bays from the wings), then remove all the control surfaces and replace them with new ones that are about three times as big. Lastly, as far as I can think, would be moving the CG back to about 50% MAC.
Dennis-