Thank’s for the reply and suggestions.
I have tested those plug-ins but they didn’t fit my needs (can’t remember what is was).
My costumers don’t always have something to comment when rating us. Now that the field is required many of them click it away and leave no rating at all.
So to increase conversion I’d think making the field optional would be a good idea. It would make the plug-in even more versatile.
Thanks for considering this in a future update!