Is Stimulant Free Pump Formula Better for Muscle Growth

I have been thinking about switching to a stimulant free pump formula for my main training sessions. I have heard that better blood flow and nutrient delivery to the muscles can lead to better growth in the long run. I am in Toronto and I am looking for a product that focuses purely on the pump and cellular hydration.

Do you think that the stimulants are actually necessary for muscle growth or are they just to make you feel like you are working harder? I am wondering if I could get better results by focusing on the mind muscle connection and the pump without the distraction of a high caffeine buzz.

Have any of you made the switch to a stim free routine? I would love to know if you saw any changes in your muscle size or your recovery. I am trying to find the most effective way to train for hypertrophy and I am curious if a pump focused approach is the way to go.