FOSS Android music players

I want a music player that satisfies these requirements:

• sort by album artists
• two way playlist syncing
• fast with a large music library
• limit to specific folder
• replaygain support

What I’ve tried:

• Apollo: no whitelist for a directory, searches everything
• Be Simple: no whitelist
• echo music: no whitelist
• howl: no whitelist
• kure music: no whitelist
• little music player: only plays single songs
• music player: no whitelist
• music player (orange-white icon): no whitelist
• music player go: no whitelist
• noad player: no whitelist
• odeon: no whitelist
• odyssey: no whitelist
• phonograph: no whitelist
• pretty good music player: can’t select sd card
• sangeet: can’t select sd card, no whitelist
• sense: no whitelist
• vinyl: can’t choose an SD card. See issue. PR that fixed this was labeled wontfix.
• VLC: no two-way playlist sync.

I’ve stuck with Vanilla Music, but there’s some bugs with importing playlists. A suggestion is to have the app running before I change the playlist, but that doesn’t seem to do anything.

Do I really have to write my own app…