If you've been fortunate enough to have stumbled upon black_falcon's itemfinder patch...
You'll know it doesn't work 100%.

It just needed a better hijack point. :whoa:
Also tweaked it a bit for two different tiles.

For every item in a room, there will be an orange tile.
If no items present, a grey one.

Details in the asm for tile placement.
There's a whole top row, idk what patches your using, just a default position.

Credit goes to black_falcon.

$8C bytes bank $80.