Have new 1/4a and 1/2a Nostalsia Pendleton Faults. I really like my Crescendo’s but with the straight rib construction, I was always re-trimming them. Rarely could I pull them out of the box and have them fly the same. The PF’s have geodetic stabs and sheet leading edge wings. Hopefully they will be more consistent. 😀
How are you storing the models? That can make a huge difference in the models staying in trim. It’s no secret that geodetic construction is best. Even as a kid I knew planes like the Tartar’s stayed in trim while the Satellites needed various trimming due to the same issue, straight ribs. That’s one of the reasons they started in later years adding the geodetic ribs. If you can store the wing and stab on the LE or TE there is little stress on the surfaces. You can also make simple jigs on your storage shelves to keep everything where you want it.
I generally check my airplanes for warps before leaving for a contest, but with the larger airplanes that are covered with polyspan I seldom ever have to make adjustments. I fly a Crescendo in Class A and I’ve never had to fix the warps. The smaller airplanes that are covered with tissue occasionally need some tweaking, but not too often. I don’t have any geodetic airplanes and I’ve never been a big fan because you can’t change the warps if you decide you need more or less washout, for example. (I know, you can glue a piece of trailing edge on, but to me that has always looked hokey and I think it increases the drag substantially on that side of the wing.)