Amperage through switch wired to Shelly2.5

I am going to wire a few blind motors, each using a separate spur from a socket circuit.

I want the current for each blind to come through the specific spur for the blind when wired via shelly2.5 and a wall switch.
The problem is this: the wall switch will have to get another live not the same as the blind.
See the following image:

My question is this: will current flow from the live on the switch to the motor? Or will it be (as I expect) from the Shelly L inputs to the blind via O1/O2?

And more importantly: What kind of current flows through the switch when using a shelly2.5 device?

I am asking this because due to house wiring, I have Live at the wall switch location that comes from some lights circuit (smaller cables) and I dont want the current for the blinds to be pulled from that circuit. The location of the shelly will be different (not near the switch).