Unless what you mean is that tightening down an IBtank onto a provari is cutting OFF airflow - an IBT ring should prevent that...
But if you've got airflow - from a flanged carto, or from not going "flush" with your tank, then it probably won't improve things...
I HATE the "gap" with a tank - my best
tanks all have air channels in the bottom.
For a flat-bottom tank, I'm probably gonna try a ring with holes...