RE: .049 sailplane set up
I flew a 2X4 with a Cox Black Widow on a Sig power pod for many years. Had good climbing ability but you always had to retrim from power to glide mode. But the plus was you could remove the power pod and use a Hi-Start or winch if you wanted to.
Now has been converted to electric, much better option in my opinion unless you just like screaming .049's
Happy Flying
Bob