Width mismatch with other plugins

xfce4-pulseaudio-plugin 0.4.9 created an item in the panel that was the same width as a standard launcher whereas the item created by 0.5.1 is slightly wider (except when the panel is configured to have a fixed icon size equal to its row size). This is normally not a problem; however, there is a very specific situation where this has negative effects:

If the user has a two-row panel with the volume control in the rightmost column (or the equivalent in other orientations), the wider volume control prevents a narrower Launcher, Show Desktop, or Application Menu item it is paired with from being clicked from the exact corner of the screen.

The reason this is worth any note at all is that moving the mouse to the corner of the screen and clicking is a much lower-precision action than moving to a specific small button and clicking. People often place frequently-used items in the corners of the screen for fast access, and having this fast access is currently incompatible with having the volume control above the fast-access item.

Admittedly, there are many ways to arrange a panel and very few where the volume control width will be a factor, so I'm not expecting anyone to jump on this as a serious issue. But documenting nonetheless.

I did confirm that this happens across multiple GTK themes and icon themes.