The ADS system has multiple rows of chambers. However, VO asks for only 1 rating curve and outputs only 1 value for outflow. Is the software conceptualizing all the rows into a single row of chambers?

What manufacturer you have selected?

For StormTech, you just need to know the number of chambers. This means it does not matter whether the chambers have been in rows or not. The number of rows is not a parameter for StormTech.
For Triton, you must enter the number of rows.
Note: You can see the design details and calculations on their websites.
There are two types of storage chambers. 1- retention system. 2- detention/attenuation.
For (1), The water infiltrates the ground. Therefore, you need to have a discharge curve.
For (2), The water exits through the outlet using a flow control device (an outlet for the whole system). Therefore, you need to have a depth-discharge rating curve.