Well, I don’t think having all of the tags in a leased scan class wouldn’t really get you very much, due to how leased scan classes work. When a window is opened, it looks at all of the tags used in it, and gathers up the scan classes they belong to. Those scan classes are then leased, and all tags contained in them (including any not on the window) would be executed at the faster rate.
[Note: Since this is a common misconception about leased scan classes, I should note that in the future we will likely make them work more like one would expect: on a tag by tag basis]
As for how it would affect scripting- disabled tags are going to have overlays and throw errors, but tags in leased scan classes won’t do anything unusual. Even if the scan class is not currently leased, it is running, at the slower rate (which could be 0, not at all). So to the system, everything’s normal.
I guess another alternative to disabling tags would be to have a slow scan class for tags that you think you aren’t using, and then move them to a faster one as you start to use them. Honestly though, I think disabling them is better, because with this method you run the risk of having tags on the screen that rarely get updated and not knowing it. Another big reason I suggested disabling them is because then they won’t even get loaded when the system starts - saving some startup time.