Can't believe I hadn't already done this, as it's so simple!
Switch-Away button
Add a KM Link button and select the below macro in it. Set the button parameter to:
<Name of profile to switch to>,<Name of profile to switch back to later>
In this example, I'm adding this button to my Logic profile and pressing it willl take me to my Smart Power profile.
SD Profile Switcher - Switch and Log Previous.kmmacros (45 KB)
Switch-Back button
Add another KM Link button and select the macro below in it. That's it!
SD Profile Switcher - Return to Previous.kmmacros (45 KB)
Both macros have a green action in which you must set the name of your Stream Deck Device. I have a Stream Deck XL, so it comes set to that by default.