Almost every song from Epic Yarn would sound nice in VIP Mellow, I think. Particularly these two. I also think that the big band cover of the Zora Band from Majora's Mask could go nicely. And a lot of songs from Chrono Cross. Though it's also worth mentioning that I joined only a few minutes ago and I'm not even sure if these songs are missing from the list or anything, ctr+f doesn't work on the playlist and I don't know where to find a searchable plaintext list of titles. Excuse my incompetence.
Oh, thank god. I would kill for a mellow update. I can assure you that most of these songs, if not all of them, are currently NOT in neither the mellow nor the main VIP. The playlist is sorted alphabetical by game title, so that helps a little bit. There are, however, a smattering of Chrono Cross songs in the main VIP. Hopefully they don't interfere with a mellow submission, as I find songs from that game enjoyable in a mellow playlist.
Back with more suggestions. I think it's odd that the website's default background is from Xenoblade, yet no music from Xenoblade appears on the mellow playlist! So why not add the night-time variation of a song that's on the main playlist: As well as a few other pieces; https://www.youtube.com/watch?v=MORt3P92HKs