Reading this maze
Diamond detour starts at row 4, column 6. Of the 42 grid positions, 30 are paintable and 12 are walls. The start is already painted; the other 29 tiles remain to be reached.
Diamonds A at row 4, column 1 and row 6, column 5 toggle the gate marked A. Start up and stop at row 1, column 6. Either A diamond flips the same gate; use a return visit to change the next stopping point. The first slide covers 4 of 30 target tiles.
The verified opening crosses 3 tiles before stopping. A breadth-first search proves a 21-slide finish from this exact starting board; that is a reference target, not a move limit. You may revisit any painted tile.
Switch A is a diamond; gate A has bars when closed and a dashed outline when open. Entering the switch toggles it immediately, including during a slide. If you get trapped, undo or restart; Hint checks the current gate and painted-floor state.