UR24C - OUTPUT knob only adjusts MAIN OUT(Balanced) Only?

Hi, this might be a silly question.

I’m using UR12 now, and thinking of upgrading to 24C because I like the idea that there are separated Volume controls for Headphone and Monitor speakers.

Reading User manual, I’ve encountered something ambiguous.

In page 5, it states as following:

6 [LINE OUTPUT 1L/1R/2L/2R] jacks
For connection to external devices or monitor speakers These outputs any stereo output. These jacks can be connected to RCA pin type (unbalanced) plugs.

7 [MAIN OUTPUT L/R] jacks
For connection to monitor speakers. These jacks can be connected to phone-type (balanced) plugs. To adjust the output signal level, use the [OUTPUT] knob on the front panel.

As can be seen, “…use the [OUTPUT] knob on the front panel.” is written only under the “MAIN OUTPUT L/R” section but not under “'LINE OUTPUT L/R”.

Does it mean the giant Volume knob in the front panel has nothing to do with “LINE OUT”?

Streaming only “fixed level” through LINE OUT is a bummer for me because I don’t have any Mixer.

My UR12 has only LINE OUTPUT and the Volume Knob controls the LINE OUT very well. So I now wonder if it is a change in 24C or just deficiency user manual.

I have a ur22c and the large knob controls the monitor speaker volume and the small knob’s control the mix ratio and volume. It is a very good system that some other interfaces don’t have.