Sorry, I have an industrial backgroundNot sure what you meant about "in food"? The circulators are somewhat powerful and the impeller is at the bottom, so they keep the water circulating and the bath at a very constant temp even when using zipper bags instead of submerging a vacuum sealed bag. I have a second circulator that can handle a 15 gallon water bath.
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Never have sous vide food.
The only "under vacuum" I did was deposit plating on parts. Many metal cleaning or conditioning or plating or passivating processes require a circulating heated bath. Parts are suspended in the bath and do not contact the tank. That's how I made the comment about side contact of the sous vide bath with a zip bag affecting dwell time and final temperature.