I did an custom override to the /event/bootstrap3.php around line 330
It did the trick. But I still think it should be managed back-end.
<div class="row mat_event_max">
<div class="col-sm-6 col-md-4">
<?php echo JTEXT::_('COM_MATUKIO_MAX_PARTICIPANT'); ?>
</div>
<div class="col-sm-6 col-md-8">
<?php echo $this->event->maxpupil; ?>
</div>
</div>
I would in future releases really like the INFO box to the right to be much more flexible. Also I would like to have the option of putting it UNDER the event description. Or maybe a left/right/under option.