How tight do you have to hold bath temperatures? I haven't developed C41 at home but have done B&W, and reading about home C41 I remember that it seemed trickier to get right.
A sous vide device makes it easy to hold a water bath at a precise enough temperature that I get C41 results at home that are indistinguishable from my local lab, at least to my eyes.
I use a sous-vide circulator to get the products ~1F above the recommended 102F for the shortest possible development time (3.5min) and never had any problems! The kit I use (cinestill) is a 2-bath process (Developer, and Blix) and not accounting for the time to get the products to 103F, developing a roll of C41 film takes less time than B&W and gives me more consistent results.
Ah that makes sense. I was doing B&W with basically a kettle and a glass thermometer, I had no electronic temperature control equipment. I think I would have found it extremely challenging to do C41 consistently without that.