I actually did something a bit similar[1], but with a Raspberry Pi 4, which has native composite out. I have it looping through Plex playlists of media that was originally released towards the end of the SD era (although most of it is high-quality HD rereleases that get naively cropped to 4:3 by VLC). I do also happen to have a Miyazaki playlist, but it starts at Nausicaä instead of The Castle of Cagliostro. I'd love to replace my cheap thrift store CRT with a nice PVM/BVM though!