Comment 4 for bug 254230

I think the suggestion in comment #1 will be very confusing. People who know
about how the feature works won't remember what they have at the top of the
clipboard (so you'll always have to check or always have to select something
everytime you want to autoscroll). People who don't know how the feature works
will file bug reports saying that autoscroll only starts up some of the time
(and I doubt if many people would figure out why on their own).

If you want less confusion for newbies, I'd suggest setting only one of the
options by default and adding a pref that lets the user choose if they want
autoscroll, paste, or both. It would thus only be the people who explicitly
select "both" that would have to learn that you can only turn off autoscroll
with a left click (since a middle click after starting autoscroll would paste).

Finally, your comment on the double-click delay only becomes relevant if someone
decides to differentiate a double-middle-click from a middle-click inside the
icon after a delay (in my suggestion both did the same thing: paste).