Like I just said in your other post, the ring has a lot of power stunt potential. In m&m the power write up is just the base template. The power stunts done while being used are the real gambit of abilities.
You don't design the ring to do everything. You design the ring to do the basic things and then stunt all the oddball things. Hal making a stethoscope to hear through a wall is just a power stunt, because its not something he does every issue.
Back in my Champions days Aaron Allston used to say if you don't see it done 3 times in the comics it's probably just writer's fiat power. In m&m those writer's fiat powers are power stunts.