In the Firefox PDF reader, when we select the highlight tool, a small selection popup constantly stays open until the highlight tool is deselected. While reading a document, that small popup on the top right is very annoying and is often intrusive. It would be a great idea to make it disappear after a few seconds after the highlight tool is selected, only to reappear when hovered over the highlight tool button on the ribbon at the top. Please look into this and consider this frature.