QU-24 Both LR Output from One Main Output

Is there a way to connect just the left or right Main output XLR to my mono amplifier and have both left and right routed through that single output? Or should I just get a splitter and plug both left and right into the splitter and have it combine to a single input on my amp? Working with a QU-24.

If you use the ALT OUT there is an option for a summed mono out there, it’s in the I/O
routing set up menu.

Do not use a hardwired Y cable to jumper the L and R outputs together.

https://www.ranecommercial.com/legacy/note109.html

I have made some of those, actually used one on a QU32 at an install.
They can be built into a the XLR connectors, the resistor values can be changed some.
Whirlwind makes a transformer based summing combiner.

Duly noted. I am already using the Alt Out for other things. Can I make the Left Alt Out a combined mono out and the Right Alt Out a second combined mono out? I wish mixers had more outs. Could I make Mix 1 an output to the amp and just send everything to that mix?

Via a dSnake stage box you can patch the mono sum to outputs.

Yes, you can use the mono mixes as well. Just set all the channels to post fader and zero dB Level.