well that is the million dollar question. Are MB's starting to come with out that as an output? I've never seen a board that didn't have a pin for it. My current board is a z77-a it has one, i have no clue about the z490 i just bought as it is not at my place atm.
My only thought is a reset switch is basically a power interrupt you can always just kill the power on the back of the PS. I have actually done that a few times when its an easier reach, i keep my comp sideways on the back of my desk so i can see inside and look at the perty lights.
Now you got me thinking about thism maybe i'll just mod the whole darn case, I could really use some USB ports and the power button on the side. Like you said switches are small, i could easily put that stuff in the front cover on the side. Hmmmm thanks for the idea!