Yes, with the FX loop you can use Input 2 for a second signal.
But this does not accomplish what I was hoping to accomplish. I want to use input 1 for my pickups and input 2 for my piezo. I also want to use the Echo function to copy Output 1 to Output 2 so I can send the same signal to my monitor and to FOH. With the Echo function, I can turn up my monitor without affecting the FOH signal. Unfortunately, when the FX Loop block is inserted in the grid, it disables the Echo function.
I had this discussion the FAS Support and in the end it came down to a new feature that I would like to see added. I have not posted it yet because I was waiting to see if we get an AX8 Wish-List sub-forum. I would like to see the ability to use Input 2 as an input with separate signal routing in the AX8 without the need to insert an FX loop. This will allow users to use the Echo Output 1 to Output 2 function. The way they have it configured now disabling the Echo function makes sense if the FX loop is being used as a loop, but does not really make sense if you want to use Input 2 for a separate signal. They would also have to add the mixer block or some other way to assign Input 1 and Input 2 to two separate signal paths since the AX8 is really set up for just a single mono input. I hope that makes sense...