Greasy Fork

function onInstallMouseOver(event) {
  let url = event.target.getAttribute("data-ping-url");
  if (!/[&?]mo=3$/.test(url)) {
    event.target.setAttribute("data-ping-url", url + (url.includes('?') ? '&' : '?') + "mo=3");
  }
}

Reproduction:

1. Find an "Already Installed" Userscript in GreasyFork
2. Mouse hover to the install button
3. See the console

(I am using Tampermonkey BETA 4.19.6183 with Microsoft Edge )

Filed as https://github.com/JasonBarnabe/greasyfork/issues/1139