AI says that Oxygen on the sideline doesn't even help much. So, your idea to slow it down is really the only way.
COPILOT: Oxygen on the sideline doesn't help much at Mile High because the issue isn't a lack of oxygen in the air (it's the same percentage), but lower atmospheric pressure, meaning less oxygen gets absorbed; plus, the 30-second rest between plays is too short for supplemental oxygen to significantly boost blood oxygen saturation for a performance boost, with most benefits being psychological rather than physiological.