The S-IVB also ongoing to thrust in a minimal amount by venting gaseous hydrogen, to help keep propellants settled of their tanks and stop gaseous cavities from forming in propellant feed strains. This venting also maintained Safe and sound pressures as liquid hydrogen boiled off during the gas tank. https://ambiq.com/events/how-ambiqs-ultra-low-power-apollo-socs-enable-energy-efficient-smart-rings/