You'd still have scanlines there. 480i is pretty much 240 lines swapping rapidly, and Gamecube and PS2 games have variable methods to de-flicker (with buffer effects) to smoothen this out on the software side (though not all of them - early PS2 games are notorious for flickering).

I personally just use a NTSC shader and live with that. It could have a CRT shader over it (crt twitter going into shaders often forget the signal part) but i'm on 1080p and i'd rather keep the 'tv capture card experience'.

I have yet to see a consumer CRT in sizes 14-21" (the most common ones) that is easy to appreciate scanlines in progressive content

Have a look to this shader. I extensively use the component profile and haven't looked back.

https://forums.libretro.com/t/new-sonkun-crt- … s-thread/39091/

There might be scanlines in theory but in practice your eye won't register them. So it's up to you whether you'd like the 240p look on 480i games. Some shader would be recommended anyway, since CRTs are not just about scanlines but many other things like dithering, glow, etc.

On that note, the modern "chunky" (and isolated) scanline look is hugely overrated, since in real life these mostly appear on >600TVL PVMs and nobody used them back in the day to play games. Depending on a type of your TV or even monitor you'd get some, sure, but they would be much subtler and also be inseparable from shadow/slot masks.