Spoke tension meter readings changed after I swapped my work stand

Last month I got one of those cheap clamping stands with the rotating head and decided to re-true a wheel I'd done a week before on my old stand. Same wheel, same spoke wrench, same tension meter. The readings were off by like 10 to 15 percent just because of how the wheel was held and the frame angle. I thought my meter was dying or I forgot how to use it. Turns out the flex in the cheap stand arm was letting the wheel sit slightly different each time I flipped it. Has anyone else seen big swings in tension readings just from changing stands? I'm trying to figure out if I need to stick to one stand for all my work or if there's a trick to calibrating around it.