So it looks like it can be done - highlight the arranger block, press P and then click on the add cycle marker button on the marker track. I also found out that the time based of the arrangement track is somehow linked to the time base of a (the first, or the active?) marker track, even though you cannot toggle the time base of the arrangement track itself, you can make it time-based (instead of “Musical”) by making all your marker tracks time based.
This became important when I got a mix project of a live gig with 24 tracks and 18 songs in one project and had to reimport wave files to “get to the latest mix” with the earlier tracks. Working with big tracks like that is still a major headache due to automation and performance problems - I guess I will throw hardware at it and get a new i9 before Christmas - the old i7 from 2016 is just too slow to handle all my plugins and big sessions.