Sending PC audio to Qu24 options

I need to get my output from windows 10 pc to my Qu24

What I have now.
I have a basic on board audio card with a 3.5mm to 1/4" adapter connected to input 23/24.
That’s working but I’m getting a hum.

Then I have USB connected and can set ST1 out of pc to Qu24.
That works but I hate having to select layers to adjust the level of that input.

Questions
Do I get a ground loop isolator for my 3.5mm adapter to get rid of the hum?
Can I “route” that ST1 input to one or both of the inputs on on the main (ie 23/24)?

You need some transformer isolation between the computer and the mixer.
Something like this, there are other makes and models as well.
https://www.whirlwindusa.com/products/black-boxes-effects-and-dis-direct-boxes-pcdihw

You get an external USB audio converter.
These work well…
https://peavey.com/usb-p-usb-playback-device/p/03001370

You could always directly connect the PC to the mixer via USB.

As for ST1 and ST2 being on the top layer you can build a custom layer and include them in the custom layer along with your other needed channels.

Thank you. This answered my question