I show 8 servings from a just made plate of whatever. In this case it was Stir Fry. But I have my servings in Retuner set at 12 servings per dish to match the number of sims I can have in a house. 

Yes, I understand the mod is displaying 8 servings where there should be 12. But can you get 12 servings out of it through the mod by calling more than 8 sims to a meal? And if not, if you serve 8 is the platter depleted or are there really 4 more servings left to be eaten?

I use that mod and have Retuner set for group servings to be 12.  The mod accurately displays the remaining servings for me even if greater than 8. However, I also use icarus_allsorts' Cook With Any Ingredient mod with which I set the number of servings manually.  Dunno if that makes any difference.

I have this issue in Deery Meadows with one of my families on their main home and it's caused by the world's creator placing that lot backwards so the back of the lot faces the road instead of the front.I learned from that to make sure my worlds are fully blank and to watch how lots are facing before setting them down in blank worlds.I make sure the arrows on a blank lot being set down face a road or walkway before placing the lot down.