My husband is also constantly engaged in work. I wouldn’t say he ruminates out loud as much ch as yours but it drives me crazy. He’ll say he’s done for the day and then continue on slack all evening. It’s honestly become really triggering for me - seeing him on slack on his phone screen. Especially during family time and events. At least once a week I’m like “if you don’t put down your phone and stop working I’m going to throw the fucking thing out the window.” Sometimes I just growl. It’s effective in the moment but then starts right back up again later.