I think it’s also how the record/ dubbing works.
As reference, I have three loopers (all Boss). They work as follows.
Press record, it records a loop of variable length (based on pressing the pedal). On pressing the pedal the second time
It will start playing the loop and optionally go into dub mode or play mode. Anything played will also be heard.
In dub mode the original loop keeps going at the same volume and anything new is recorded at the same level.
On two of my pedals I can sync to a clock. In both cases you can set the length of the loop and have it tempo synced.
I think a lot of this can be done with the existing units, but not necessarily the easy workflow on dubbing.