It looks like they have dropped support for the P4 with the release of 3.1.4 for Android so it seems we are now stuck to using GO4 with its crappy video downlink and app crashes etc.

Just because they have stopped upadting the original version Go app, doesn't mean you must abandon it.
You can still use it (if you want to) or use Go 4.

In the release notes for 3.1.4 it states that support for P4 and Mavic Pro have ended so assumed that it would no longer work with them.

G1DTF Posted at 2017-3-21 06:05
In the release notes for 3.1.4 it states that support for P4 and Mavic Pro have ended so assumed that it would no longer work with them.

That just means that they have stopped further development of the app.
Microsoft ended support for Windows XP years ago ... but you can still run that if you want to.

G1DTF Posted at 2017-3-21 06:05
In the release notes for 3.1.4 it states that support for P4 and Mavic Pro have ended so assumed that it would no longer work with them.

Not the case at all, I used Win98SE, XP and now 7 long after "support" was stopped and my first move with any software is turn off auto update. In fact I rarely update anything unless it has proven advantages for me because why run the risk of introducing problems to something that is already working properly. "If it ain't broke, don't fix it" and with all due respect to DJI they are a classic case of a company who introduces "updates" that turn out not exactly so.