I’ve never ‘topped’ tomato plants as I have a shorter growing season than some, anyway. (Zone 5) I DO make sure they are fertilized on time, and I pinch out any suckers, for sure!
BUT - if you’re gonna do it, here is a guide on what to do and when and why:
https://www.tinygardenhabit.com/topping-tomato-plants/
Great question and good Food For Thought! :)
Thanks that was the info i needed.