Advice/expert-opinion? Best quality for showing on a TV

I have a question about video quality and which method will look best on a 4K TV...

Facts:
- I shot all my source clips at 3840 x 2160 (4K)
- in my edit... I *zoom in* on a lot of the clips. I shoot really wide.. then stablize .. then zoom-in on the action. Many of the "key moments" are probably a 2000x1000 resolution zoom-in.


I have three choices for creating output videos
1) Timeline 1920x1080 resolution and output video at the same 1080p resolution.
2) Timeline 4K resolution, render for 1080p output (maybe this is the EXACT SAME result as above?)
3) Timeline 4K resolution AND output 4K...yes, even though that means Resolve will be doing upscaling of my zoomed-in clips. the question.. will this look BETTER on a 4K tv than having the entirely-1080p output scaled up by the TV? or will it look worse?

Same question for YouTube ...

thanks for help/advice

Best practice would be to keep it how you have it, as you probably have some native UHD assets (text, graphics etc.) and shots that are not zoomed in as much which will benefit somewhat.

To be honest in my experience the difference between a native UHD signal and an upscaled HD signal on a UHD TV is very minor at normal viewing distances - all other things being equal. Compression type matters a lot more in my opinion.

But if the speed/file size benefits of HD are not really a factor, your probably better off outputting in UHD.
Something like UHD Prores(HQ) is a great codec to use for youtube.

You could also try resolves superscale to see if that gets you a better looking result than the standard algorithm when scaling up some clips.

Also, to your option 2), no it is not quite the same, things are still processed at UHD and then downscaled to HD for the output, I wouldn't recommend it for mastering over 3) or 1). Generally the less stacked scaling operations to shots the better (ideally just 1 or none).

Like Matt, I find the HD to UHD upscaling of displays to be very good, so I would choose one of two approaches.

1. Edit in HD for the "punch ins" and let the TV upscale.
2. If I had a good enough GPU, edit in UHD and use SuperScale to get the "punch ins".