[noggin]

I must say watching 1080p@50Hz looks pretty good on my 4k Sony Android TV with Kodi v16.1 PT installed

Can you watch any 720/50p or 1080/50i native news channels with tickers (the scrolling text at the bottom of the screen)? The BBC News Channel ticker in the UK is a great test of motion rendition (if you see it at 60Hz it screams 'wrong' to me)

I'm not from the UK so can't watch it officialy, but a 25fps stream of BBC News looks the same on RPi or my TV.
Would be handy to have sample files we could test these sort of problematic combinations

25p streams are much trickier to see this on than 50p or 50i streams. The BBC News Channel is a 50i native source, so you really need to watch a 50i or 50p version of it for full motion quality, which will show the 10Hz judder introduced by repeating 1 frame every 5 to get from 50 to 60 really clearly.

The 720/50p BBC News Channel stream in iPlayer in the UK shows it very clearly on platform that can access it (Android, Apple TV etc.) and the 1080/50i or 576/50i off-air DVB-S/S2/T/T2 stuff really shows it (and with the 50i stuff you can also see how good the deinterlacing is as well as a bonus!) Not sure if the 720/50p live channel stream will be available outside the UK.

(One of the best things the BBC have done recently is to introduce 50p encoding for their iPlayer Catch Up TV platform - with both 960x540/50p and 1280x720/50p profiles added to the adaptive streaming - so native 50i stuff like sport and entertainment is now available in full motion at 50p, not half motion at 25p, on supported platforms. It's made it close to 'off-air' quality)