Does the Edge like to pitch to the belly on vertical uplines?
I had a H9 Edge that would pitch to the belly in torkrolls, and it would also pitch very slightly to the belly in uplines. It might be that you built the plane with some stab incidence, and thats whats doing it. You might want to check it and re-do it if its not right. especially if you plan to use it for IMAC.