That’s an interesting idea! The gate sensor would essentially shrink the geofence to the actual perimeter of the property, by not checking the presence sensor until I reached that point. Combined with the zigbee presence sensor, that might solve both the bus stop problem and the chatty neighbor problem.
I understand your point about the mode change as well. I need to capture the “arriving home” moment vs “being home.”
Thanks, I’ll try it! 
Edited to add: the more I think about this idea, the more I see multiple possibilities with different kinds of devices, such as a motion detector, a pressure mat, the open/close sensor you detected, etc. Once one of these is combined with both a presence indicator AND a special “transitional” mode, I can get some very precise geolocation triggers. So I can switch from Away to JD Arriving Home to Home.
Or Home to Yard to Home again.
It’s going to take very careful tracking to make sure the modes work just the way I want them to, but this may solve a couple of use cases for me, both the bus stop problem I’ve mentioned previously and the dog in the yard issue I mentioned in the topic I link to.
@Tyler had suggested I solve the second set with custom code, but while I can code, I don’t want to. (Even cut and paste is a pain when you’re reliant on text to speech technology.)
But with your approach by combining a presence sensor, a second trigger device, and a transitional mode, I think I can do everything I want with Hello Home Actions. 
With the understanding that if I’m not really careful setting up the mode changes, I might run into an unexpected failure to fire.
Thanks again, I’ll have to play with this a bit and see how it works out in practice.
OK, using @digitalm0nkey 's idea, I have now worked out a new occupancy identifier system, but requires multiple modes and devices. Still, it should solve the problem of momentary drop offs.