Now you've completely changed the experiment. If you stop the timers at the destination, you haven't measured light.
Dude, I'm not coming in to correct you on this comment chain. You don't know what you're talking about at all, even a little bit. You are just ad hoc adding things to an experiment that does not at all address the problem.
I'm going to recommend this book to you: https://www.amazon.com/Relativity-Explained-Classics-Science-Mathematics/dp/0486293157