Again and again
Geoff,
Some old stuff here. In the 365 series, I always operated and advocated the night/IFR takeoff to be initiated from the get-go hard on the instruments. The old ITO if you may.
I always placed the heading bug on the expected initial turn to heading and activated the heading hold after take off and normal climb attitude was attained plus known obstacle clearance altitude reached.
This worked well for me for many years. But when *** took over SAW, their training department shot me down with vengeance. Their stance was to have the heading bug on the take off heading and activate the heading hold as soon as airspeed allowed then let "George" manage things.
In my opinion, a pilot who is solid on the scan from initial power application through climb to cruise flight attitude is less likely to lose situational awareness than one who uses automation so early on in the take off run.
Cheers,
Gray