Nice, thanks for playing. Good idea about a way to have a persistent map or a way to extract that doesn't require going back to the extraction point. That wasn't in the cards for the 7DRL – I ended up not having anywhere near the whole week to work on it - but maybe if I expand the game later, I can add some features that lead in that direction.
In the mean time, you can use the coordinate tracker in the upper left corner to keep track of where you are on the map, allowing you to make notes of important areas like the extraction point, portcullis locations, energizer platforms, etc.