Yet another post on disabling middle button click behavior on touchpad

[Milwaukee73]

I've Mint 21 with Cinnamon 5.4.12, and my browser insists that my touch pad should have a middle button. I don't like that.

I've never used a middle-button on mouse, and my touchpad isn't set up for that (marked with left side and right side).
Yet a stock Mint/Cinnamon install responds to the middle button with the browser. In particular, it opens a link in a new tab and deletes an existing tab.

I've wandered thru the site, and the advice so far seems to be to go to the mouse and/or touchpad applets and -- do something. Yet there is nothing there that says "Middle button will do this action: ...".
Enabling "enable middle button thru left + right click" doesn't change the behavior.
I get the behavior with "Default device behavior" and "virtual button areas along bottom of touchpad".
If I choose "Use multiple fingers for right and middle click" I get changed behavior, but i don't really want that to be my solution.

Is there some other configuration for middle button clicks on a touchpad?

My Asus UX430 laptop is using the libinput10 drivers, not synaptics.

Thanks,
Jerome.