i plan to get a similar setup (music on homeserver, synced to phone for offline use) but i dont need to sync playlists as i rarely use them, i have a streaming account with one(!) playlist with all the songs i remembered and wanted to listen to but didn’t buy as CD back then and use the radio like streaming options a lot.
but for syncing phone with nextcloud i use FolderSync (Pro) and it works as it should. it has lots of possible sync targets and lots of options to sync one or both ways. i have folders with >8000 files that take some time to sync but it works fine in the background with no prob, i let it sync over mobile network too, cz i value a more reliable in-sync status more than bandwidth. however i didn’t really try “immediate sync” for new/changed files yet as i don’t see the need for this but its one of many options.
however i only use nextcloud sync in one or two-way syncs and once used sftp for a one-way sync, so i cannot judge all the other options, but if your playlists are organized in files, their two-way sync might be as easy as with the songs. i bought the pro version on their website so my license is not bound to a google account.
First contact was on the here-named eta-carinae system, we did a holiday tour there long ago and heared about earth from a scientist that rescued a human instead of just studying and thus could not leave him there with his memories about him. the human was talking about star trek, its similarities and real differences all the time. he already spoke fluently in standard Sjesh/sound w/o any interfaces so we listened directly to his true mind. he even had a very worn out tng tshirt in his personal memory items box. i mean he really had used his memory items before! that made us curious and the rest is history. However he is now back here, as we managed to arrange his behavioral training to hide his experiences well, he passed all the tests and got his transport back, but with his biologic cells clock reset to his 20th to compensate the decades he lost out there a little bit. it is possible he could become an ambassador for earth one day, but it looks unlikely that he would want that given the circumstances here, a task he always compares with the mytholigical boulder of Sisyphus (that really never existed physically) whenever he is asked about his opportunity.
just kidding, first contact with TNG was in school, other kids talked about the first episode. i could not watch it at home and also had other problems to fix at that time so i missed a lot of the start of it :-/
however i am trying to train myself for writing in general as i have ideas for a longer story (but not within the trek universe) and as the above text came to my mind i just wrote it and hope you don’t find it too misplaced here or badly written… however any feedback is welcome.