https://lucene.apache.org/solr/guide/8_2/managed-resources.html
In docs there is info:
PUT/POST is used to add terms to an existing list instead of replacing the list entirely. This >is because it is more common to add a term to an existing list than it is to replace a list >altogether, so the API favors the more common approach of incrementally adding terms especially >since deleting individual terms is also supported.
Is there some way to force POST request to replace all managed resource on endpoint, instead of adding terms?
Solr version 8.2
As an answer to myslef - no there is not. You can fork and change it in source.