If docked to a edge the indicator should be at the edge of the dock (like in OSX) instead of the edge of the icon (at least that's my opinion). Could just have so that you can set the position in the options for Nexus of how the indicator should be placed, but when loading a new skin it goes back to the "default" position. Or possibly have a setting to switch if the indicator is located inside the icons boundaries, or at the edge of the dock itself, and then have the posibility to change a value for how much to shift it up/down from that position or so. You could also consider adding a setting for placement of the indicator for skins so that if the setting exists in the skin itself, it changes the position of the indicator, if no setting exists, it uses the default position. In the end it's up to you in what solution you make and how you make it (and if you make it).