Welcome to the community
It should not be very hard to set up a flow like that, when “contact alarm” is on then start the timer (you need a timer app, (multiple available), when the contact alarm is off stop the timer. And when timer X reaches 30 minutes sound alarm, send notification, etc.
Also, you can connect Eufy to Homey and still have notifications etc, I use a second account in Eufy to connect to Homey. [APP][Pro] Eufy Security (first post). That way your old solution would probably still work too.
Just made a really simple example that you could do in normal flow or advanced flow, haven’t tested it, and of course you can add more criteria or optimize it. This is just an example.
