My overall experience is that (managed) CLB is the standard and default mode. OP CLB only used when no choice (HDG) or actively wishing to ignore FMS altitude restrictions.
As if
ATC gives radar vectors or clears the aircraft to a give FL without any climb constraints.
meant
when ATC tells you to ignore those constraints.
I see the point that
ironbutt and
pinteam make, just in my area it is considered appropriate to have CLB instead of OPCLB when possible. Basic design philosophy:"all managed, all pushed".
Check Airman I usually wait for "almost" full N1 before activating the climb to avoid that. BTW in your situation, I would had flown exactly the same modes, most likely forgetting and ending with the same result ("oh nintendo, was that really necessary?!"). Being a rather fully managed man myself, I do not consider operational choice of sel spd or V/S in busy airspace a sin.
vilas I ran out of vocabulary praising you a long ago, but this one is a real diamond.