You can send me an email to robert.dickinson@gmail.com or robert.dickinson@autodesk.com or robert.e.dickinson@innovyze.com and I will do my best to answer your questions. Autodesk Inc bought Innovyze Inc on 4/2021 so I have multiple work emails now.
I have noticed based on email questions and postings to the SWMM LIst Sever (a great resource hosted by CHI, Inc.) that many SWMM 5 users do not know about the really outstanding documentation on SWMM 5 posted on the EPA Website https://www.epa.gov/water-research/storm-water-management-model-swmm It consists of two now and in the near future three volumes on Hydrology, Water Quality, LID’s and SuDs and Hydraulics. The documentation is fantastically complete with detailed background on the theory, process parameters and completely worked out examples for all of the processes in SWMM5. It is truly an outstanding aid to modelers and modellers worldwide. It would benefit you to read them (if you have not already downloaded the PDF files). Thanks for reading this post