it's the same SDK, so devs will simply update their app to include support for the new P4 sensors/modes. Everything else will remain backward compatible. ie, there will be 1 Litchi app that supports both birds. (that'd be the smart way to do it, anyway, if nothing more than to minimize code maintenance).
The other guy did. I was letting him know there's a place for that now. We don't need to hear about it in here.
And to be completely accurate, you didn't mention it by name, but your title and your reference to the new and improved drone? I think you know what I mean.