Video iFrame size for hi-res screens

I’m lucky enough to have a 4k monitor at home (I do a fair bit of hobby photography and design work; and in more recent times I need the 4k for working at home).

When I’m using the website though, the iFrame size used in the react-player DIV is really small once rendered (only around 15% of my screen width and height), this means that I frequently end up jumping over to YouTube to use ‘cinema mode’ to get a ‘nice’ video size on my screen (which means I lose all the website functionality, such as note taking, etc.).

Is there a possibility to have a hi-res screen layout for the website added to the dev backlog please? I realise that this is very much a ‘First World Problem’ (and that the YouTube API might not permit this)!

Alternatively, is there a nice workaround that I’m missing?