Reset Xfce4 Application Finder Size

Looking under ~/.config/xfce4 I found ~/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-appfinder.xml

In there, there was a "property" XML node named "last" containing several other nodes, "window-height", "window-width" and "pane-position". I deleted the whole "last" XML node with a text editor, restarted the computer and now AppFinder spawns where it used to. Afterwards the AppFinder itself rewrote the configuration file with the default coordinates.

$ tail ~/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-appfinder.xml 
      <property name="save" type="empty"/>
      <property name="command" type="empty"/>
    </property>
  </property>
  <property name="last" type="empty">
    <property name="window-height" type="int" value="400"/>
    <property name="window-width" type="int" value="400"/>
    <property name="pane-position" type="int" value="180"/>
  </property>
</channel>