I just use the IPHONE WIFI presence sensor for my daughter. When she arrives her phone connects to our wifi and that sets a virtual switch. I then use that switch to determine alternate rule capabilities while she is here. I think you can do the same with Android phones. Arrival is almost instantaneous, departure is a bit trickier, as the iPhone will connect and disconnect as it goes to sleep and wakes up. So I use a rule that if her phone disconnects and stays disconnected for more that 8 hours it turns off presence. That in just in case I forget to turn it off on the dashboard when she leaves.
Since most folks these days have wifi in the homes and everyone has a phone, This works well for us. As mentioned above, you have to set up each device to a specific IP, which means they need to turn off the feature on the IPHONE that spoofs different MAC addresses.
For other guest I just have a routine on Alexa that I can say Alexa, we have guest and it turns on the guest switch.
