Had a good talk with DH this week about why we were having so much trouble keeping the screens-off time and lights-out time we had picked (I actually had him pick the times, in the hope of more buy-in). I was frequently closing my computer and switching to a book well before him, and having to remind him when he tried to show me something that it was past screens-off time. Same for lights-out, I would get up from reading 15-20 mins before and get ready for bed, get a glass of water, set up things for morning, and come to bed, only to have to remind him that it is lights out time and then he would want to finish the chapter before going and getting ready, and we actually go to bed half an hour after the proper time.
After the chat, we agreed that it isn't working for him to go to bed the same time every day, but it is working for me (I feel much more rested now than before we started), so we are moving the evening computer and reading time downstairs. It is not as comfortable or warm, but this way I can keep track of time and go to bed when I need to, without nagging or interrupting his flow. We'll try this for a few weeks and see how it goes.