Currently, I am a beginner to intermediate level UE4. I wanted to expand into VR using the engine as well. I do not have any VR equipment and wanted to make an educated choice based on how it works to develop it using unreal.

The main question is tethered vs untethered for development purposes. When you are actively playtesting and running your game while devloping, how does an untethered (occulus quest) work? Do I have to fully deploy and download the game everytime I want to see how it plays in the headset? For tethered systems (Rift S), when you hit play in UE4 and it is plugged in, can you see the game being played as if you were working with it on the PC? 

Note: I'm not asking what VR system is better, i'm asking how does the debugging and actively playtesting the game work through UE4 based on a tethered vs untethered VR headset.

I haven't used an untethered system before so I can't comment on that.  With HTC Vive (which should be similar to the Rift), once you press play in the UE4 editor, the game will immediately begin playing in the headset.  Playtesting and debugging is a bit of a pain in VR, you are constantly putting on the headset and taking it off, which is why I haven't done it more.

Thank you for your response!
I still am very curious about the untethered development process.