Repair and Optimize Database throws warnings clustered index

[BenMak]

When running Repair and Optimize Database I got following Message:
Warning: [mysql error 1105] ORDER BY ignored as there is a user-defined clustered index in the table 'pi_stuffs'
ALTER TABLE pi_stuffs ORDER BY id; in /var/www/html/piwigo/include/dblayer/functions_mysqli.inc.php on line 856

This is a table created by the PWG Stuffs plugin.
The Database Optimisation attempts to sort the table pi_amm_blocks by id. This is rejected by MySql as this table is already sorted by the (clustered) index.
Either the plugin needs to be modified so no clustered indexes are created in tables or Piwigo has to change the Repair and Optimize Database module such that tables with clustered indexes are skipped from re-sorting.
Any suggestions?

See also https://piwigo.org/forum/viewtopic.php?id=30714