openbox rc.xml application size
3. 6. 2018This
<application class="Obconf" name="obconf" type="normal">
<size>
<width>45%</width>
</size>
</application>
or longer
<application class="Obconf" name="obconf" type="normal">
<size>
<width>45%</width>
</size>
<position force="no">
<x>center</x>
<y>center</y>
<monitor>1</monitor>
</position>
</application>
https://forums.bunsenlabs.org/viewtopic.php?pid=72844#p72844