I did this once with a foam propeller jet called an Electrajet from e-flite. Did not work very well. I think the problem was that I got it too light and could not maintain enough speed to generate enough lift on the wing profile.

I ended up putting the motor back in. It still did not slope very well but it was better with the weight back to its normal flying weight. You can see where the speed 400 fit between the tails.

After that I just took any "power" planes that I wanted to fly on the slope and just tossed them off. Either they flew well or they didn't and I always had the motor to recover if things went badly.

I slope a variety of gliders, e-gliders and have sloped a few electric planes too.