I have not understood the post of Laprodo (why did you need to hack the php?). I have configured a new page mosaic_template and the addon works fine
Very nice!
But i've to hack the php.
At first I've change $thumbpath = ltrim($cfgrow['thumbnailpath'], "./"); to $thumbpath = "./thumbnails/"; /* ltrim($cfgrow['thumbnailpath'], "./"); */ because $cfgrow['thumbnailpath'] is empty in my case
An than I've spaces in my image names, so I've to change $mosaic .= "<a href="index.php?showimage=$pieces[0]"> </a>"; to $mosaic .= "<a href="index.php?showimage=$pieces[0]"> </a>"; to ensure loading.
Perhaps some stuff for next version.
Thanks a lot for your work!