Sensitive child

Hello, we just started implementing TSG principles a few weeks ago, and it's been a huge adjustment for our family. Our son has always been very sensitive and feels the need to feel heard. This week I gave him an instruction while he was in the middle of something school related. Instead of disagreeing appropriately, he got whiny and started complaining that I wasn't taking into account his schedule or what he was doing. He started to get agitated so I started to go into the rule of three, which irritated him more because he felt I was not listening to him and interrupting him. He earned the first two consequences and got himself calm enough to speak to me in a respectful way even though he was crying. He said that when he gets agitated, all he wants is to know that he's being heard so he asked if it would be ok for him to take 30 seconds to speak uninterrupted in these situations, even if he becomes a little emotional, before going into the rule of three. I told him I would think about it and decide during the next family meeting. My thought is that maybe right now I should aim for progress, not perfection? And maybe if he can manage that then start expecting him to be fully calm from the get go? Your thoughts are appreciated!