No worries duckman06
In this economy I have to work with lots of different customers, they might be general contractors or homeowners. A lot of people are looking to save money where they can. So that means working with them on what they will do and what I will do. Just did a complete 4 plex with all new duct work. The contractor wanted to use his guy for the duct work, since they gutted the whole building. fine. They understand if it has leaks that's on there dime.
The guy did a great job. We passed HERS testing.
Duct work is an art and a science. Meaning there are tricks that can be done that don't show up in design software. One tip. On really long runs (over 25')
I will make sure the duct is a bit over sized, then right at the vent will use a reducer to speed up the air exiting the vent. For example I did a 25' run of 12" and Y into to two 12' 8" runs and then reduced to 6" right at the vent.