Something I often do to control the spacing at the top is simply remove the background and styling from the popup itself and then style a group inside to look like a popup.
If the popup should close when clicked outside, then I add a workflow to the popup element to close itself on click as well as an empty click workflow on the group so that the popup doesn’t close when the group is clicked.
The only “issue” - and it’s a minor one - is that the mouse pointer changes to the “hand” when over the spacing region. Works just as one would expect though.
-Steve