Hey Claus, I'm a Traktor user myself, and because I needed Rekordbox compatibility, I developed the DJ Conversion Utility (DJCU).
DJCU is macOS only, here is the tutorial, and some other info you might want to check out.
From Traktor to Rekordbox(xml) Quick Tutorial DJCU 4.0 [MacOS]
From Rekordbox to a CDJ USB and tips for first time CDJ users
DJCU is compatible with Rekordbox 6, but you need to be aware of the Rekordbox XML import bug, it's not a show stopper, just annoying.
Rekordbox 6 and the DJ Conversion Utility (DJCU)