Motion was an issue for me, but most say it isn't. Buy one of the Z9D televisions and try it out. Current return for BB is into January, so plenty of time to try it out. The supply will diminish on those now whereas the 900F will still be available. If it is a problem, take it back and get a 900F. Or, if your budget allows, get both and return the one less favorable to you.
I have no idea on the Nest app.
The 900F is no slouch. It is what I went with.
OLED77C9PUB // 5.1 Infinity Reference (RC263 / R263 & R162 / SVS PB-1000) & Denon x1600 // Xbox One X & PS4 Pro