Sounds more like crew incompetence than any specific airline procedure. Some crew are just plain stubborn/scared/oblivious when it comes to amending SOP's in non-standard situations.
I have been in a similar situation. No APU, no ground aircon, 30+ degrees and a dispatcher keen to close the doors on time even though we had a slot. A firm NO settled that issue. And I demanded steps to be put back in place at the rear door so both doors could be kept open till slot time. I'm sure most of us woud ave done the same, but there is always that 10% of idiots in any airline..