One thing you can do is place a token on the map, give it a name, "Chest A", show the nameplate, allow control to "all players" and remove all player permissions. To the players, the token looks like part of the environment. If they click on it however, they will see that it is indeed a token. They can tag it with a color or symbol which would clue the GM in on who opened or attempted to open "Chest A". The GM could have a handout available called "Chest A" with the contents and perhaps some GM-only info about any traps or whatever. Show the handout to a player or players. Not exactly what you were asking for, but it may still work for you.
