One golden rule when you buy tv - get yourself portable ssd and upload all high quality sample videos. Test with them videos before making purchase
Considering OLED philips models based on same hardware I would expect same issues there with video lags etc... tv boxes like yours with coreElec uses hardware just for running os and playing your video, where on philips its all shared with other processes.
Like I said I have mi box s which is nearly identical spec, but philips tv just no where near it, mi box flies over these videos with no lag, but this tv just bug on bug all over places