This is one way to set the volume to a value for all devices at once.
Create a logics numeric variable. This holds the volume (a number from 0.01 to 1)
Set the number to f.i. 0.5 and then run this flow:
But it is quite “unfriendly” in daily use
I prefer this idea:
Create 2 virtual knobs
These knobs then operate these flows:
Of course you can set smaller steps by setting the relative volume to +5% & -5% f.i.
And of course you can use a real knob to trigger the flows, like Ikea buttons
