A few weeks ago I asked for a precision about the alias feature:
Why physical ports with original name starting with the backend client name
are renamed to "system:(playback|capture)_N"?
It causes a problem on interfaces with a lot of I/O. For example, the MotU
828mkII has 22 inputs and 22 outputs. It's more difficult to find the phone
out labeled system:playback_11 and 12 than dev0_pbk_Phone-L and R.
One other important thing with MOTU interfaces is that the number of I/O
varies depending on the clock frequency and the interface configuration. For
example, on the 828mkII, @96kHz the ADAT out use 4 ports against 8 @48kHz.
ADAT can be completely disabled.
In this case, numbers in ports label doesn't make sense.