Allow mult-input

I typically use two guitars on gigs, a Strat and Les Paul. I would like to be able to plug the Strat with its single coils into QC Input 1, and the Les Paul with its double coils into Input 2. Then I would like to configure the input in path 1 to be Input 1 + Input 2 so that both guitars go through the same signal path. The eliminates the need to use up a whole path just to combine the inputs.

Another advantage of this is that I can adjust the input 1 & 2 levels to more closely balance the two guitars into the the rest of the signal chain, and don’t need to use a gain block to do this.