I looked at this again. While I have no workaround for the above (Having arranger mode wait for input after re-entering), I think I now understand that the Arranger-chaining function is meant for what I want.
A limitation is that only one chain-jump can be scheduled at any given moment and doing that involves going into menus (yikes). And there are only eight slots of course.
Once scheduled, a selectable row appears at the bottom, when you select it and hit YES it will execute. So my apprach is to first insert a loop-row at the end to avoid accidental stopping upon the arrangement reaching itās end. This way, the āchaining/jumpingā becomes optional and you can trigger it in a deferred way whenever you want.
This way the arranger to me is not merely a song mode, but more of a notebook or route-map which helps me remembering possible places to go. I mean otherwise, how the heck are you going to memorize which patterns are relevant out of the 256 patterns? Arrangements can also be named. I donāt enjoy entering text on the OT, but itās probably worth doing.
In hindsight I wish there was a quicker way to schedule the āsongsā, I mean with a single button press, like the regular chaining .
EDIT:
Upon reflection I realise that this not too different from what I thought of doing before after all, which is creating independent sections withing a single song, using āloopā-rows as boundaries. This way even saves you from visiting the menu. The inevitable forced jump when re-entering arranger mode is the real annoyance after all.