[Elecraft] K3: Separate monitor level for phones/speaker ?

[Iain MacDonnell - K6IAM]

I like to use the monitor function to tweak my outgoing audio, using
headphones, but I often operate "casually" with a speaker and boom
mic. With the monitor level set to a useful level for adjusting my
audio with the phones on, it causes feedback when on speaker, so I have
to keep turning the level up and down.

It occurred to me that it'd be nice if the K3 could remember separate
monitor levels for phones vs speaker? I'm not sure if that'd be feasible
for "SPKR+PH" mode, but if it could at least work when that's off... ?

As a side-note; when I turn on "SPKR+PH", the right-side of my phones
goes quiet - receive audio moves to left only. Is this normal/expected??

     ~Iain