Nope - just tested this and I can't get out. If there's proper place I need to click I couldn't find it. Secret area usually have two doors, one on each side - would a dev please confirm if it's me or a bug? Thanks.
The second quest - Sewers generator area contains a secret room that's only one way. You can enter but you can't get out.https://i.imgur.com/9r4hlzU.png