The upscaling in Kodi is pretty confusing. I would propose to simplify it to the Zidoo method. Two options. Either match frame rate, or match frame rate and resolution.
If match frame rate and resolution is selected, then all resolutions are sent to the TV as is, and the TV does all the upscaling.
If simply match frame rate is selected, then the box does all the upscaling.
Kodi’s method with the whitelist is confusing as hell. If you set 4K GUI, then box does all upscaling unless you configure whitelists for every resolution. If you set 1080p GUI, then native 1080p content is upscaled by the TV, while anything lower is double upscaled unless whitelist is set.
I think Zidoo has the right approach here since nobody wants both Kodi and TV to both upscale. Either the TV does it all, or the box does it all, and it should be independent of the GUI resolution. Just two options keeps it sweet and simple.
EDIT: I actually prefer Kodi’s upscaler to the TV. These algorithms are very well known and the processor in the TV is not necessarily faster or better.
My LG G2 is powered by the alpha9 processor, no details are given on RAM/CPU, but anyone trying to play MKV or MP4 remux from WebOS can immediately see that performance is much worse than our S922XJ boxes. WebOS in general is slow, glitchy, and laggy. It’s not just OS issue, but plainly seen on playback. That’s why even on streaming apps people prefer ATV or Shield Pro to the TV apps.
Why would upscaling be better on the TV then? I’ve tested many many times, and have always come back to Kodi’s upscaling vs the TV. I think the S922 isn’t a weak chip, and the HW may even be better than what is within the TV.
Of course this is all preference / opinion, but I just don’t think TV upscaling as a rule is better.