Yes, this is very possible. Use a counter to count down with triggers from 30 to the door opening. Also find a reason to trigger the counter to start, whatever that may be.
For randomizing a gadget change, use this guide:
Yes, this is very possible. Use a counter to count down with triggers from 30 to the door opening. Also find a reason to trigger the counter to start, whatever that may be.
For randomizing a gadget change, use this guide: