Depends on how much yaw stability you want. Also depends on how much mix you want to dial into the set up.

I don't have the plane's parameters so not certain but it sounds like the fore CG is fairly close to the 25% Mac region. At this location the model probably has a more locked in feel. With the aft CG, pay close attention to the directional feel of the plane and compare that to its fore location.

Do the same for knife edges, both sides, both locations. The smaller wing will help reduce amount of mix you need for straight flight in knife. Ideally you want no mixing of rudder to elevator.

If the model has a roll tendency with applied rudder, the wing dihedral isn't precise. Rather than building a whole new wing if you don't want to mix, you will be able modify the dihedral effect by modifying the smaller wing. That is adding anhedral or dihedral to the smaller panel, depending on what the plane needs. This is one time when a small rud to ail mix may be necessary but if it's more than a few %, some unwanted subtleties may creep into certain advanced loop-roll combination maneuvers.

Its all all about the trim you like