[Uoppi]

Just a quick one to make sure: is all upscaling performed by the TV's hardware when running the Kodi app on a Philips Android TV (with Surface ticked on, as it is by default)?

Or is only the 1080p -> UHD upscale done by the TV? In other words, how is for example 720p -> UHD upscale performed - 100% by the TV? Or first by Kodi from 720p -> 1080p and ONLY THEN from 1080p -> UHD by the TV?

(On a side note, being "stuck" at 1080p@60Hz with no frame rate switching is surprisingly a non-issue. I'm sensitive to jerkiness/judder but the Philips 804/854 appears to handle motion very well at all frame rates when Clear Motion is on. I've tested with all frame rates and the interpolation/pulldown works great without flickering or SOE. I used to mess with HTPC/Kodi/DSPlayer/madvr for quite a while and after that it's a resolute "no thanks" from me to external boxes and tweaking).

[Uoppi]

When displaying video in "Original" size (vs. "Normal") in Kodi, anything below 1080p is rendered in a smaller size on the screen. Only 1080p and 4K are shown in their normal size. 

Based on this, and correct me if I'm wrong on any of these points, but I assume this means (similar to Bravia TVs):
1) 4K is passed through to the TV's hardware as-is.
2) 1080p is passed through to the TV's hardware upscaler as-is.
3) Anything below 1080p is first upscaled by Kodi to 1080p and only then passed on to the TV's hardware upscaler.