Also keep in mind that most airlines have a restriction in their OPSPECS to not commence a circling approach unless it is 1000 and 3, far above the minimums for circling.
While I fully agree that the training to circle in simulators is solely useful for... well, circling simulators ----- the notion that joining the FAA's "1000-3 club" will make circle to land maneuvers just as safe as a flying VFR traffic pattern is simply rubbish.
Circling MDA's provide no more than 300' of Required Obstacle Clearance.
Maneuvering beneath a 1000' ceiling may --- or very well
may not ---provide additional margin above the dirt/trees/rocks/obstructions.
Please -- high HAA's
do NOT imply additional ROC.
IMO, the concept upon which the referenced OpSpec has been predicated is fundamentally flawed.