Sorry, I missed this. Hopefully you'll see my reply. Lag certainly was a problem for me with earlier pi models as well. The Raspberry Pi 4 doesn't have the lag

Sorry, I missed this. Hopefully you'll see my reply. Lag certainly was a problem for me with earlier pi models as well. The Raspberry Pi 4 doesn't have the lags, or at least I don't experience any. It's actually smoother than my laptop with YouTube videos. And it's quite fine with both hdmi ports in use. Probably not multiple videos at one time, of course.