Restaurants Checkout - Change Google Map location

As Wix Restaurants doesn’t support multiple sites yet, we have a workaround where the customer is presented with a product modifier to select the pick up location. Our customers typically only buy a single product so this flow works well for us, until the first checkout page. The google map shown is the corporate address which is confusing to customers when their selected pick up address is miles away. I can see that the map is pulling the co-ordinates from the site backend (using wix-site-backend.getaddress() maybe?), but cannot see a way to edit the call or #onlineOrdering1 as I can’t find a way to change the contents of the iframe (id elements seem to be kept at such a high level I cannot see how to get to individual fields using wix code).

Is there a way to:
a) dynamically change the google maps address
b) hide the map completely and replace it with an image

Many thanks,

Tim