Using supportedButtonValues, the details view is different between app versions. 1.7.72.21 shows only the actions specified, 1.7.73.22 continues to show everything. Both show correct actions when used with automations/routines.
Clicking, then canceling, on an action not specified in supportedButtonValues results in a quick undefined event message.
Yes, there have been a few reports of that. I am seeing it on Android with my own custom handler but I notice the one IKEA button I have, running a stock handler, is still đisplaying correctly.
Yes, this issue is only happening in the Detail View and is already reported. If you want, you can set a device-config using enabledValues to define the allowed button values but it would be static. Even if you changed the supportedButtonValues, the presentation would decide what is displayed.