and you can't edit different categories at the same time.
You can select all the duct, add liner, then select fittings, add liner, but can't just window the entire run at one time.
Duct liner REALLY needs to be an adjustable parameter you can set as you construct the duct, preferably in a pull-down right next to duct size.
That seems like a simple-enough request.
If I really wanted to get fancy, I'd ask for the ability to tag my duct with airside dimensions (sheet metal - liner).
Ed