My understanding of the workflow for 2 tracks of audio is just that.
I “break it apart” —>
“Clip | Expand Audio Compnents”
and then in the I turn to “Stereo Left/Right”,
which I think is what you are looking for.
And IDK if there is a way to have this setup as a default for every timeline.
FCP X 10.2.1 – user since FCP 1.25
iMac mid 2011, MBA mid 2012
iPhone 4
HVX-200, Shure wireless mic
Miller Solo tripod
Advanta-Jib