Sometimes it’s the simplest things that get overlooked. When mounting tires, are you checking the bead is seated evenly? All the way around? On both sides? Not pinching the tube?
If you care about true wheels, you should care about true tires. You should give this topic special consideration if you run tires with supple sidewalls (e.g. Compass/René Herse) and it’s mandatory to ensure your tires are well-seated for stable tubeless applications.
Last month I replaced a worn set of tubeless tires with fresh rubber and overlooked the bead not being seated evenly in one spot. I achieved a tubeless seal so surely everything was fine? No — over a span of a few centimetres I allowed the bead to fold under itself. It was immediately obvious that alignment was lost because a big wobble developed in the rim. I inspected it in the truing stand and the wheel was physically out of lateral true by over 2mm! I pulled the tire off and the wheel sprung back to fine form with runout less than 0.2mm (that’s also low spoke count wheels for you).