Hello, Jim. Happy Thanksgiving!
Yes, the LCD module on the Balboa 32U4 is compatible with the 2×7 LCD pinout on our A-Star Prime, and this LCD that we recommend for use with the Balboa 32U4 and our other ATmega 32U4 based robot control boards will also work on the A-Star Prime. (Although please keep in mind if you get an assembled A-Star prime with the LCD included, the LCD will come with a female header soldered on that will make it impractical to use with the headers on our the Balboa control board.)
For the LCD I linked to, DB0-DB3 are only used in 8-bit operating mode (the files on its product page under the “Resources” tab have more information) , so those pins being grounded on the Balboa 32U4 mean it can only be used in 4-bit operation mode. If you are only planning to use that LCD and our libraries then that is probably not a problem. However, if you decide to use a different LCD, please keep in mind the A-Star Prime can support an 8-bit option that the Balboa cannot.