The rep probably said that because he/she couldn’t find the word “Optimus” anywhere in the specs, but any laptop that has both an Intel and an NVIDIA GPU supports Optimus. If it didn’t, then the only way to use the NVIDIA GPU on the built-in display would be for the system to have a more complex and expensive wiring design and for you to reboot the system and change a BIOS option every time you wanted to use the NVIDIA GPU, at which point it would be running all the time and severely decrease your battery life. That’s not how this system works.

However, be aware that if the external display outputs are ALSO driven through Optimus rather than THOSE being wired to the NVIDIA GPU directly, then you wouldn’t be able to use technologies like G-Sync, Adaptive V-Sync, VR, or stereoscopic 3D even on external displays. Most systems have all outputs wired to the Intel GPU to preserve battery life at times when you might be using an external display/projector on battery power. Some gaming-oriented systems instead have at least one output wired directly to the NVIDIA GPU specifically to be able to support the technologies I just mentioned (especially VR), but I’m not sure if that’s true of this system. But if all you care about is Optimus, you’ll have it.

Outstanding info which corroborates what I had come to understand. Thank you so much @jphughan  . I will have to see about VR support on one of the external video outputs. With a total of three outputs it would be delightful if not anticipated to have one of them serve toward this purpose.

Cheers

@pluriel  happy to help!  In terms of VR, be aware of a potential pitfall there.  On the gaming systems that have a display output wired to the discrete GPU, it's typically the HDMI output, because the initial wave of VR headsets used HDMI.  Some still do.  However, the new Oculus Rift S switched over to DisplayPort.  DisplayPort video output can be achieved from a USB-C port that supports video output by using a USB-C to DisplayPort dongle.  However, on every Dell system I'm aware of that has a USB-C port that supports video output, the USB-C port's video interface is wired to the Intel GPU.  The only exceptions I know of are the Precision 7000 Series models from the xx20 onward, which have a BIOS option that allows you to choose which GPU controls the display outputs.  They achieve that with a more complex and expensive motherboard design, but I haven't seen that implemented elsewhere.

So if you're trying for VR, you might have to give some thought to which VR headset you want to use, because if you have a system where only the HDMI output is wired to the discrete GPU, then you can't use a DisplayPort-based VR headset.  There are DisplayPort to HDMI adapters, but they don't work in that direction.  They can only convert a DisplayPort source to an HDMI signal, not the other way around. 

There's also a new standard called VirtualLink that is backed by all major VR headset and GPU manufacturers that is basically a new way to configure a USB-C interface to carry enough power, video, and data to run an entire VR headset from a single cable.  It's expected to be used on future VR headsets.  I may be wrong here, but I don't think it will be possible to retrofit VirtualLink support to existing systems because VirtualLink basically involves running USB 3.0 traffic over pins on the USB-C connector that the current spec reserves for USB 2.0 (in order to increase available video bandwidth by reconfiguring the typical USB 3.0 pins for video).  That said, I don't know of any VirtualLink headsets on the market yet either, and I would expect that they would include some sort of breakout box that would separate that link into power, USB 3.0 data, and video so that those headset can be used from non-VirtualLink systems, but even if those existed, they would need a DisplayPort signal from the host system rather than HDMI, because again USB-C uses DisplayPort for video.  Unfortunately, as I said earlier, finding a system that has a USB-C or DisplayPort connector wired to the discrete GPU might be tricky at the moment.  This will probably change on gaming systems going forward, but obviously that doesn't help if you're trying to buy a system today.

No, Intel UHD Graphics is desactivate... 

imagine steering people to save battery instead of using the graphics card of a ""gaming laptop"" becuase drrr duhh drr, muh battery life. you are about the most useless rep here. shame on you