My company interprets the B737 FCTM circling procedure, where it states:"do not decend below MDH untill intercepting the visual approach path" as maintain MDH until in Final, lined up with the runway. Try to do this with 2400 meters visibility.
The visual approach descent segment used to be +/- 30 of C.L. On a circle procedure using 3 x AGL/000's you should roll into the 60-30 degree cone with 2R 2W. You need to descend. If you stay level until on C.L. surely you'll end up 4W and diving. Not good if at only 500' to start with. If within the segment and visual why can't you descend to attack/maintain PAPI's to assure the stable landing gate; or would they rather you risk being unstable and landing long?