I don‘t understand how this works when you say you practice your serves after you go over to the non-sun side if you start on the other side first. The way we play tennis is that we call the toss, the teams choose serve/return/side etc., we switch to the side picked, warmup including our serves and then start the match. How is it possible to practice serves on both sides of the court in an official match?
Even in social play, I’ve rarely (if ever?) seen someone make a request to warmup serves from the opposite side of the court once they finish warmup on one side. I’m a lefty too and if I end up warming up serves on the sun side even though I plan to serve on the other side during the match, it is not a big deal. I’m not going to ask my opponents to wait after the warmup while I run over and practice serves from the other side.
Am I missing something in how you do it?