"Add new track" via the plus sign, assigns the track directly to my Octa-capture.
That's new for me.
Normally it is routed to the Master bus, which is normal for me.
Is there a point to this?

Does not work that way for me.
 

• If the project has a default bus defined, add track uses it.
• If the project does not have a default bus, add track uses the first audio device output stereo pair defined in preferences.

 
Either way an alternate output may be selected from the output drop down in the advanced section of the "Add Track" UI.
 
IOW, inserting a track with the Add Track menu works the same as the other methods. Double check the project has "Set as Default Bus" enabled on a bus.