I think the issue is that helium does not become a solid at 0k at 1atm pressure while hydrogen does. So one needs to do these experiments under less than 1 atm

I think the issue is that helium does not become a solid at 0k at 1atm pressure while hydrogen does. So one needs to do these experiments under less than 1 atm pressure when working with hydrogen or higher temperatures which may then not result in a superfluid state?