So, what do air correction solenoids do? I assume air mixture control, so how will I know if they fail?

Started working on cars couple decades ago, done plenty of 80's Honda cars where carburetor is attached to a black box by no less than 40 vacuum hoses, each controlling some air circuit or another essentially last step before EFI. This 2 solenoid NSR thing seems much simpler I was hoping someone has a clear idea how it works and what symptoms to expect when it fails.

I know it is all tied in to PGM2 and provides 3D ignition and fuel mapping (I assume air correctors work based on RPM and TPS so that would be a 3D fuel map)


And back to my high idle question: I get 3000 rpm on a cold bike with no choke, comes down to 1500 after it warms up a bit, any ideas? Is it normal?