It's been a few days and I have a workable system in place now that I wanted to share.
Here is the schedule for when the player opens a chest:
The chest has a instance variable called "Chest_ID" which is unique for each chest (in this case, it is the chest in Buster's house). When the chest is opened the schedule sets a webstorage key with the same name as the Chest_ID and sets its value to "opened". Keep in mind that this example is using session storage rather than local, this is just for testing purposes to allow me to easily reset all the values without having to wipe my browser cache, it will be set to local in the final version)
And this is the schedule that runs at the start of the layout to check what chests have been opened:
So, when the layout begins it checks the relevant webstorage key for Chest_ID "BH_1" and if it set to "opened" it will run the chest opening actions.
It isn't the most efficient way of doing things, but it allows me to determine what loot each chest contains, which is what I want.
I hope this is useful, and if anyone can see a way I could make this more efficient please let me know!
slap it onto the flappy bird template...
bang it on google play with all the other shovelware...