Chessplosion's Dungeon mode now has a map screen! You can access it from the pause menu and use it to warp to any previously explored room.

Here are the full patch notes for update v2716:

• Dungeon: Map screen added. You can access it from the pause menu and use it to warp to any previously explored room.
  
• Bugfix: Opening the control config menu from the adventure world map or the puzzle editor no longer softlocks the game.

Edit: Update v2718 adds a dedicated button for accessing the map screen. The default button is Tab (keyboard) or Y (gamepad), and you can change it in the controls menu.