Below is from the internet only manual, they describe using units to identify the number of services performed. I was unable to find any guidance of billing add-on codes on separate lines with the 59 modifier.
FL 46 - Units of Service
Required. Generally, the entries in this column quantify services by revenue code category, e.g., number of days in a particular type of accommodation, pints of blood. However, when HCPCS codes are required for services, the units are equal to the number of times the procedure/service being reported was performed.
Chapter 25 - Completing and Processing the Form CMS-1450 Data Set [PDF, 471KB]
Above is from 100-04 Chapter 25 of the Medicare Internet only manual Page 34
Below is from 100-04 Chapter 26 of the Medicare Internet only manual Page
Item 24G - Enter the number of days or units. This field is most commonly used for multiple visits, units of supplies, anesthesia minutes, or oxygen volume. If only one service is performed, the numeral 1 must be entered.
Some services require that the actual number or quantity billed be clearly indicated on the claim form (e.g., multiple ostomy or urinary supplies, medication dosages, or allergy testing procedures). When multiple services are provided, enter the actual number provided.
For anesthesia, show the elapsed time (minutes) in item 24g. Convert hours into minutes and enter the total minutes required for this procedure.