Thanks for the pointer.
I had already done the equivalent by traversing the list using [color=#bb0000]array_reverse[/color] when writing the on-page notes list.
This has the same behavior as changing the query, including that a new note is not at the top until revisiting the page.
in .../modules/mod_cnotes/tmpl/default.php

...

<div class="cnotes-notes">

     <?php if (count($items)) : ?>

        <?php $items = array_reverse( $items ); ?>

        <?php foreach ($items as $item) : ?>

        <div>

            <span class="title">

                <a href="/<?php echo JRoute::_('index.php?option=com_cnotes&task=note.edit&id=' . $item->id); ?>">

                    <?php echo $item->title; ?>

                </a>

            </span>

            <?php echo $item->note; ?>

        </div>

        <?php endforeach; ?>

    <?php else : ?>

        <span class="cnotes-nothing">

            <?php echo JText::_('MOD_CNOTES_NO_NOTES'); ?>

        </span>

    <?php endif; ?>

</div>

...

I have made several other changes including a bug fix on the page that writes out all your notes:
components/com_cnotes/views/notes/tmpl/default.php

On that page, I removed an extra ">" that was showing up as a list of one ">" per note and I did some better column headings.

I know this is a free module that was done in a class. Is there a way to submit changes to it?

Ordering of your notes can be accomplished by changing the file mod_cnotes/helper.php .
Change lines 23-25 from

$query->select('*')->from('#__cnotes_notes')

            ->where('created_by = ' . $db->quote($user->id))

            ->where('url = ' . $db->quote(self::getUrl()));

to

$query->select('*')->from('#__cnotes_notes')

            ->where('created_by = ' . $db->quote($user->id))

            ->where('url = ' . $db->quote(self::getUrl()))

            ->order('id DESC');

Only drawback: the new ordering only will be visible after a 'hard' page refresh, so not immediately after adding a new note.

Regards
Gerlof