Full open, not backed off. Diving in side and no mount caves I bump my valves against plenty and have never had a hard time closing any of them...but apparently others have, so in the battle of the anecdotes, siding with caution, it sounds like leaving them fully open is not good.
But I'll keep diving with mine open. I have had fill operators who don't open them fully get confused and have to check the tanks when filling sidemount tanks.
But I'll keep diving with mine open. I have had fill operators who don't open them fully get confused and have to check the tanks when filling sidemount tanks.