OP - sounds so like my DH, he sees more black and white than shades of grey ITMS???.
Some things that have helped here are making sure we do regular and routine food/water breaks, rather than waiting until they lose the plot and i haven't realised. Early dinner is important here - so asap as we get home on a work night and about 5.30pm on home days. Hard as we try to eat together and this is not always possible. Work days I have a heat and eat meal ready or sandwiches as they have a hot meal at cc.
Also trying to give enough time to get out the door - so half hour rather than 5mins. DD2 likes to change clothes/shoes and whilst I HATE it I am trying to let them have influence over the few things that they can rather than dictate everything.
Good luck!
ETA - You sound super organised - I know DH having the kids without me as back up did change his expectations as well. Enjoy your weekend!