@BDiamond, the approach I mention, while you are using the "assign people to a room" mechanism, is only being used to create the room names. Unfortunately you can't just put in room names - you must include an email address. Here's an example of the full process... it looks long, but it goes by quickly and saves time in the long run, in my opinion.
To do this, you (or your account admin) will need to enable the "Allow host to assign participants to breakout rooms when scheduling" option one time following the instructions in this Zoom Support article:
https://support.zoom.us/hc/en-us/articles/206476093
At a recent event I produced for a client, they had a poster session with 10 posters; I created 10 breakout rooms with the following spreadsheet (the original also had the names of the presenters embedded in the title):

(I included the "Poster Number" at the beginning of the Room Name.)
Once you've created the CSV file, go to the meeting edit view on zoom.us. Enable the Breakout Room pre-assign option in the Meeting's Options section:

Then click the Import from CSV (you can create the room list on the fly, but I prefer to do it in a CSV file):

Drag and drop (or browse to) the CSV file:

A confirmation window comes up, where you can edit the information (note that the names on the left column are occasionally incomplete; the full name appears at the top on the right):

When I go into my meeting and click the Breakout Rooms icon, this is what I now see:

Set the Options you want, and when you Open All Rooms, all your rooms will be there.
The pre-assigned name I added to each room isn't shown... since nobody with that Zoom account email is present in the meeting. Doing this for each meeting will save you time... just go through this import process once per meeting.