ONIX Boutique Bern review for Shopify Search & Discovery

Customer SUpport was friendly when i ask them following: "The Problem is thet when my Costumers choose for example the size XL in the Filtersection, it's also showing all the Products wich have the XL as a variant, even if the XL for the specific Product is sold out.... That makes absoluetely no sense to me... Is there any way to solve this? " The answer: "So Selina, it is currently expected behaviour that the size option will still show up in filters when the variant is out of stock. This is a current restriction when using the Search and Discovery app. You are welcome to try other apps for collection filtering, or alternatively, you can try out apps that hide sold out variants from the store." This App is absolutely useless without this feauture.... why even bothering to put such an app on the marketplace? It seems like Shopify makes their Apps not good enough just to myke us pay for paid Apps.... ??? Sorry, no othe way i can explain this to me. A proper filter function is crucial for allmost every shop.... Shopify still can't even add such a basic function that is working, but prices just went up. i am on Shopify for some years and i was expecting better... Also the URLs that the app i generating are very ugly: https://www.exampledomain.ch/collections/kleidung?filter.v.price.gte=&filter.v.price.lte=&filter.v.option.gr%C3%B6%C3%9Fe=XL&sort_by=created-descending