Hmmm I am not sure about that in most models. In most cases we are talking about dropping the rear of the existing wing rather than extending a portion of the wing rearwards then dropping it as the airliners do.

I have seen a few large scale models with the ability to reproduce the full size effect of moving the flap back the dropping it. Gordon Nichols B52 was one such model. I was lucky enough to see this in it's construction phase and he used screw jacks to move the flaps backwards and down. I think he had problems synchronising the jack motors to get the flaps to deploy together.

Still simple flaps are a lot of fun to mess with but they are just another thing for a beginner to have to do on the landing approach esp. as they usually bring an elevator trim change with deployment. I would not reccomend them on a trainer.