Hi Tom,
I have built 3 other planes before this Kitfox SS7 that I am building now and yes, you should test your plane in as many configurations as possible to know YOUR plane, not the spec's printed by someone else. Each plane comes out a bit different, just take your time with loading the plane to full aft weight. I fly my planes with a close to center CG as possible for the first 10 hours than start working with load going to the most forward and than work to the aft CG. I used 50 lb bags of horse feed to load up the plane as needed.
You need 40 hours anyway so make good use of the time. I added VG's on my Rans S-7 at 20 hours and was blown away by the results, stall went down into the low 30's with full flaps.
Have fun with the journey