I realize now I probably did a bad job of creating a narrow question 🙂

I ended up just going with

"what I've done so far is to add "EmployerId:<EmployerId>" to the concatenation of that computed column and then append that onto the query"

As a solution

So I added the EmployerID to the computed column that's used for the full text index...

And then all queries coming in I prefix that on the search string so that it filters down by employer first and then returns relevant results..

Worked great

Haven't had a single block on gatherer ever since and search is running faster then ever...