RE: LOWERING COMPRESSION
Sure you do, Brian.
But most people think the ring seals in the cylinder due to the fact that it springs out, which is a very partial truth.
Since many members here do not have as much knowledge as you do, I mentioned the drag-race pistons, to illustrate the idea.
Some newer examples have holes drilled just above the ring and some don't relying on the pressure that blows-by the crown, as in normal engines.