You can try the following:
I did not check if there is a possibility to override the roksproket layouts in the template manager, since I do not use roksproket, but you can find the tags part of the mosaic theme layout here:
in yourjoomla/com_roksproket/layouts/mosaic/themes/default
folder in item.php
file.
If you open that file and // comment out
the lines from line 59 to 67 then the tags will not show up anymore in your mosaic item layout on your pages.
So this part of the code has to be commented out/overriden or deleted:
We do not need the ugly tags here:
<?php if (count($item->custom_tags_list)) : ?>
<ul class="sprocket-mosaic-tags">
<?php
foreach($item->custom_tags_list as $key => $name){
echo ' <li class="sprocket-tags-'.$key.'">'.$name.'</li>';
}
?>
</ul>
<?php endif; ?>
This action does not influence the tags on any other parts or layouts of the sites, only where these mosaics are displayed.
I hope this can be in help of you.