Just to chime in, if you have more than one polished PB, you can query them all, just separately. For example, some agents wishlists match manuscript A so you query them with A. But other agent wishlists match manuscript B so you query B to them, etc. If one agent rejects A, but B or C might be a good fit for them, too, then after a few months, you can certainly query that agent with B or C.
I highly recommend keeping a spreadsheet so you can track all of this info. I started querying in 2009 and by the time I signed with my first agent in 2017, I had about 10 manuscripts I was querying on and off and would have never survived that without my spreadsheet, LOL.
And I agree with Debbie's advice, too.