The backup .mbz file contains
<plugin_qtype_match_question>
<matchoptions id="1">
<subquestions>1,2,3</subquestions>
<shuffleanswers>1</shuffleanswers>
<correctfeedback><p><img src="https://moodle.org/pluginfile.php/134/mod_forum/post/868553/zonenouvelle.jpg" alt="x" width="577" height="401" /></p></correctfeedback>
<correctfeedbackformat>1</correctfeedbackformat>
<partiallycorrectfeedback><p><img src="https://moodle.org/pluginfile.php/134/mod_forum/post/868553/imag010-2.jpg" alt="x" width="520" height="390" /></p></partiallycorrectfeedback>
<partiallycorrectfeedbackformat>1</partiallycorrectfeedbackformat>
<incorrectfeedback><p><img src="https://moodle.org/pluginfile.php/134/mod_forum/post/868553/nanoqam-1.jpg" alt="nn" width="375" height="85" /></p></incorrectfeedback>
<incorrectfeedbackformat>1</incorrectfeedbackformat>
<shownumcorrect>0</shownumcorrect>
</matchoptions>
<matches>
so the files are correctly backuped.
In the database the main question feedkacks are stored in the component question and the subquestions images as component qtypematch filearea subquestion
So the code seems correct with the 2 processes.
More later
Pierre
Pierre