I'm pretty sure that if you have a custom title, custom stars, or custom staff powers, that they will not completely convert over to v5.
I didn't use staff positions that came with the forum. I created individual groups for everyone who has a position of authority.
I do not have a mass list of everyone who has one of these customizations. You can PM me in advance if you'd like, and I can generate a list. Otherwise, we can wait until the forum upgrades, and you can then notify me if you lost your moderator powers and/or custom profile settings.