While that's true, the top ring is exposed directly to heat, it's not how a modern stack of piston rings works:
The top ring seals the chamber, providing compression. It does this by sealing against the lower ring land of the piston, and the cylinder wall. This is why it has a rounded shape where it contacts the wall, and why the top ring is the only one moly coated to seat fast.
The 2nd ring is not a compression ring by design. It's designed to scrape residual oil left by the oil ring stack off the cylinder walls prior to the top ring passing by on the intake stroke. Otherwise you'd be sucking a lot of oil up the walls and into the chamber... It can trap some pressure above it if there's too tight of a gap, or too much oil going past the 3rd ring stack. But it's by design not supposed to, and pressure below the top ring but above the second can push the top ring up off the ring land, losing some compression and allowing for ring flutter and lost power and rpm potential.
The 3rd ring package is actually two oil scraping rings and and expander to kep them pushed against the cylinder wall. It's designed to scrape the oil, and give it a path out and away from the walls - so it's not any type of compression-sealing ring.
You certainly can run the rings at what you specified. It's how the factory 40 years ago did it and it's won't be any worse. But - times change and technology improves.
