Surely this is similar to a night departure at somewhere surrounded by terrain where performance requires a climb to MSA within the circling area prior to departing on track.
No that shouldn't be done either! All HC RPT departures require performance analysis for obstacles and the operator must publish obstacle clearance procedures.
Look at 1.6% net climb engine out (for a twin). Will you make obstacle clearance altitude or circling altitude on runway track before leaving the circling area?. No, youll get to 400' at 4.1 miles and things are getting awfully tight for a turn at 15 degree AOB. Chances are the circling altitude is not going to be reached for another 4.1 miles and by now you are on downwind.
Turning into the circling area after departure is a plan for hackers who really have not thought things through. It should be forbidden in an operators SOPS. Go straight ahead in the splay. Then hope your performance engineers have calculated your takeoff performance to get over whatever comes next or they have told you to turn onto a track that avoids terrain.