After a lot of trial/error (and heartaches) and posting on this forum, I want to post something that will help everyone understand how syncing iTunes and Tagging works and what workflow to follow. This may have been explained in the past, but with more people using Rekordbox and its plus pack, I think this topic deserves some attention. The first thing to understand is how Rekordbox relies on iTunes:
RB opens > RB opens/scans your iTunes XML > The tag info displays on screen in your iTunes tree.
If you update your tags in RB, you need to consider the following:
1. You are writing your ID3 tag straight to your sound file.
2. You are not writing tag information to an iTunes XML.
3. iTunes doesn't know that you are writing ID3 tags to your sound file.
4. If you open iTunes, you will see that the Tag information is incorrect.
5. If iTunes does not display the new tag entries, RB will not display the information you have updated on the next restart.
6. If you force rescan of the tag in RB (there is a refresh button in the Info panel), RB actually scans the file itself, not the XML, to display Tag info only the duration that RB remains opened.
7. This does not resolve your issue when you quit and reopen RB since RB always scans the XML from iTunes and not your sound files.
What to do if you are editing Tags in RB and have iTunes sync'd up?
1. Tag your sound file(s) as you normally would, BUT
2. Refresh your iTunes library so tags can refresh, that way
3. RB can pick up the XML that you now have updated in iTunes.
RB does not write back to the iTunes XML. This is where your problem lies where you are trying to ensure seamless tagging.
RB writes ID3 tags to the actual sound file only and not the XML, but loads and reads the XML and not the sound file's ID3 to retrieve tag information. At a glance, it doesn't look right at all. But you can still make it seamless - you just have to go back in iTunes and tell it to refresh your tags.
It's just like getting pepperoni pizza for take out and they forget the pepperoni. Pizza dude hands you a cheese pizza anyways and charges you for pepperoni. Absurd! The order isn't right. But you can still get a pepperoni pizza - you just have to go back and get the order it fixed.
One thing to note: Sync Manager has nothing to do with this. For new RB users, Sync Manager is aimed specifically for EXPORT mode (that's why you see it in EXPORT mode only). Sync Manager is a feature to sync out your RB collection to a USB stick to play on RB devices like a CDJ-2000.