Would aggressive alarms be of any help to make sure you can get unfocused from the thing you’re focused on and moving to the “getting to the right place” part? I’ve “forgotten the time” when it’s just me setting a time for me to do something, but when I need to be somewhere for/with others I make sure to set my alarms earlier and more of them to keep myself from having “just enough time”. And I have to make sure I actually respect the alarms, I’ve made the error of thinking “I have 5 more minutes before I need to leave” so I just start leaving when the alarm goes off now.

I don’t know your exact situation, so this may not be of any help, but it may help someone, somewhere.