Yeah I thought about color coding locked gates on the map, but the only color we could've used for the borders other than the one we are using is the one we use for the player marker, and I felt that would be too confusing. As of now the only sides of rooms that have borders on the map are those that are just walls or those that are locked gates, which lose their border when the gate is open, so for now you just have to memorize rooms that were dead ends on the map before that now show an opening.
Thanks for playing, I'm glad you enjoyed!