Advanced Wireless Settings

Good stuff from KBeatty above - I'll add my $0.02 on those settings and a couple others...

First, there are a heckuva lot of moving parts both with Orbi itself and environment-dependent factors that can make or break performance from one cusotmer to another, so while my Orbi setup works really awesome for me, YMMV...

I have a basic 1-router-1-satellite Orbi setup.  The Sat is ~20-25 feet from router with a "Good" wireless backhaul connection (ethernet wired connection not a option in my house).  The router is in my basement and sat is on main floor - a couple of walls are in between too.

Daisy Chain

I recommend enabling this feature only if you have multiple sats that link like this: R-S-S.  If you have just one sat or your multiple sats are hub-&-spoke (S-R-S), then leave Daisy Chain disabled.

Implicit Beamforming

It's my understanding that implicit beamforming is only potentially helpful for older non-ac wireless devices (i.e. b/g/n 2.4-only devices).  I only have a few of those in my house, and they connect perfectly fine with beamforming disabled, so that's where I leave it.  I've experimented with having it "on" too, and didn't have any issues, but I also didn't notice any improvements. So, in an effort to just keep things as simple as possible, I leave that option disabled.  

It's also my understanding that explicit beamforming (specifically for wireless ac devices) is inherently built into Orbi - there's no seperate selection option for that explicit beamforming capability.

MU-MIMO

I'd bet almost anything that you don't have multiple mu-mimo devices that could potentially take advantage of this feature (such devices are still quite rare).  Enabling MU-MIMO offers no advantage if you have only one (or none) MU-MIMO devices. Even with multiple MM devices (which is very uncommon), the performance gains of this feature are minimal at best.

I don't have any such devices at all, so I leave this feature disabled.  To paraphrase one of the wise old-heads on smallnetbuilder.com, MU-MIMO is the "3-D TV" of the wifi world these last couple years -- a lot of glitzy hype, but no real substance ;)

Fast Roaming

I have this feature disabled, since it caused my phone to bounce back-&-forth between my router and sat wayyy too much.  I am very dependent on wifi-calling, so that's how I noticed it.  My wifi-calling is super stable with this feature disabled, but it's certainly worth playing around with in your own setup - maybe it'll work great in your particular environment.

Wireless channels (2.4 and 5)

I've always left mine at the default since those work fine for me, but I'm in an uncongested area.  If you are in a more congested area, it's definitely worth analyzing your overall local wireless environment to determine the best channel selections for you, but that's good advice for setting up anyrouter - Orbi or otherwise.

UPnP

As I've dione with every router I've ever owned, I have this feature unchecked (disabled).

I don't have any devices that no-kidding require UPnP, so disabling it keeps a potential security loophole closed.   I have some devices that say they require UPnP, but those have always worked perfectly fine with UPnP disabled on all of the various routers that I've ever owned (Orbi, Asus, Linksys, etc).

Good luck!