I just pushed a hotfix which should resolve the issue with being able to tap the ‘X’ to remove placeholder tiles on iOS devices. Thanks again for reporting it.
PS. I looked into the device in question that you would like to glow when it is active… it reports itself as a button and a switch. I have a few ideas on how to achieve your desired functionality and I’ve added it to the hit list.
Edit: Switches are now prioritized over Buttons for device display. (reference)