Talk with the instructor you will be working with. I'd be happy with a DM that could "hover" nicely in a position other than the "buddha". It's nice when you brief students that it does not matter if they roll to their side, or on their back, as long as they hover, and then have someone demo the "skill" in a number of positions. It irks me when the DM working with immediately goes into a picture perfect pose and stays there.
In my limited experience, I see some students who can hover, but struggle to remain upright, thereby using their hands and feet - gotta start the clock over again. Position is not the point of the "skill". Learning the relationship between breathing and position as well as capacity of your lungs vs. BCD is the point.
Keep at it and work on a hover that allows you to hold your knees and feet so you can show the students a way to hover without moving their hands and feet as RJP mentioned. At some point in your demo, allow yourself to roll onto your back so that they can see the hover in a different position.
In my limited experience, I see some students who can hover, but struggle to remain upright, thereby using their hands and feet - gotta start the clock over again. Position is not the point of the "skill". Learning the relationship between breathing and position as well as capacity of your lungs vs. BCD is the point.
Keep at it and work on a hover that allows you to hold your knees and feet so you can show the students a way to hover without moving their hands and feet as RJP mentioned. At some point in your demo, allow yourself to roll onto your back so that they can see the hover in a different position.