The Model 990 (which also uses the 49400) has auto-setup of levels and distances. I think the support for EQ was added some time after the 49400 was released, however - Sherwood had a revision to the P-965 that allowed for it - and reports I heard on it were underwhelming.

Supporting this with a 49400-based product requires extra hardware (gotta have the microphone, obviously, and probably some extra memory as well). It also requires more firmware complexity. Retrofitting it into an existing product would be a tall order - and retrofitting it into a product with no calibration mic would be impossible without basic re-design of the unit.