I changed the line "The maximum number of employees allowed to be hired. This assumes\n all perks have been unlocked.\n ', tunable_type=int, default=3, minimum=0)" in the busines...
The tuning data is in businessEmployee_Restaurant_Chef and businessEmployee_Restaurant_Host. These are in the GP03 tuning data, so make sure you are looking there (i.e. not the Base Game tuning data).