That is the configuration yes... but here is the difference as I remember it:
The pid controller at very low throttle can only move below the set throttle position by the "elbow room" it has to zero. In beta flight the elbow room to zero becomes a matching limit on any requests made above the actual throttle position to keep things in balance. With air mode activated - the pid controller can increase a throttle command without this limitation. Essentially this gives the pid controller just a hair more authority with a true air mode than it has with only an idle up. This is why idle up is less likely to bounce on landings than airmode in betaflight. But airmode has more authority than idle up at zero stick in the air.
In silverware, the pid controller functions differently - closer to a true air mode with only an idle up switch.