What is the right way to limit a full text search query to some rows of a table?

For example, I have a table that contains the following columns: title, content, owner (each row represents a document). The owner column is a username. It feels right to store all documents in one table, instead of having one table per owner. In particular because I'd like to full text search all documents, only documents owned by one user and documents owned by a set of users.

I tried to combine .rows_where("owner = ?", "1234") and .search() from the Table class but I don't think that is meant to work. I discovered .search_sql() as a way to generate the FTS SQL statement. By hand I can edit it to add a AND [original].[owner] = :owner to the where clause. This seems to do what I want.

My two questions:

1. is adding a AND ... to the where clause actually the right thing to do or should I be doing something else (my SQL skills are low)?
2. is there a built-in to sqlite-utils way to achieve this?

Right now I am thinking I will make my own version of search_sql() that generates a query that contains an additional owner = :owner for my particular use-case.

Bonus question: is this generally useful/something to add to sqlite-utils or too niche?