I know you have had good results with keeping communications open rather than closed with your H, but for my H, I get better results when I give him space when he's having temper tantrums. I just try not to take in his hurtful words, as he often changes once he calms down.
I'll say it again - your children need to have their own feelings, and if he doesn't like their negative reaction to his attitude, THIS IS NOT YOUR FAULT. Have him talk to his kids, rather than you being in the middle.
