I understand that in previous versions, there was a preference in about:config that would let me adjust the delay in ms that I would need to hover over a tab until its tab preview is shown. This preference is supposedly located at browser.tabs.cardPreview.delayMs but when I searched for it in about:config it did not show me any results. Any Google searches do not point me in the right direction either. Does anyone know what I could do to adjust this delay anyways?

Attached is an example of the tab preview I'm talking about.