There has been a lot of talk about the SE's CG. I fly mine with the CG 1-1/4 back from where Sig says to have it. It has no bad habits with it back there.
I have seen guys balance them at the point where Sig says to but they run into the problem like you did about adding a half pound of weight. Not good on a 4-1/2 to 5 lb plane.

You are probably balanced as is. Try it and see if you like it.