With 2021 Wave 2 came the new search functionality which I am sure will be very good, however we started developing our Managed Solution in 2008 and many of our tables are not available for the search because the attribute "can enablesync to external search index" is not enabled. Interestingly though any tables added in the last couple of iterations, I think since version 8, have this attribute set to true, but older tables do not.   We have updated our managed solution to have this attribute enabled however when applying the updated managed solution to existing deployments this attribute is not updated. 

So at this stage our existing clients are stuck, they have lost their old search and cannot use the new one.  

Any assistance would be appreciated.