When reading a Wikipedia article on my desktop computer (e.g., https://en.wikipedia.org/wiki/Rembrandt), I sometimes select the text that I'm reading with the mouse. This may help maintaining or enhancing my concentration. I believe it is not unusual. When I do this with text that has many links, the pop-ups that you get when dwelling on a link (like article or reference previews) can get quite annoying.
I don't think there's any need to keep showing those pop-ups while a mouse button is pressed. So, I propose to suppress them while any mouse button is pressed. When a mouse button is released on a link (e.g., to stop selecting), the pop-up should not appear until you move the mouse cursor from the area out of the link onto the link again.
(In this context, it is worth mentioning that it's also suboptimal to get a pop-up when alt-tabbing to a browser window with a Wikipedia tab when the mouse cursor is accidentally over a link.)
The linkDwell() function seems to be a relevant code spot here.