It sounds like you’re trying to add solar screens via the Window Type dropdown. The best way to add them is to set that control to “No Improvement” (or some other type if you are replacing windows) and use the Exterior Treatment controls below to specify your screens.
The shade coefficient is set via the “>>” button, NOT using the Add/Edit Items dialogue box where you add or edit window types.
To add 80% shades, select the shade type from the Exterior Treatment dropdowns for each side of the house, then click the “>>” button. Set each side’s attenuation. 0.20 = 80% shade.
Use the Bid> button to go directly to the Window area of the Bid Form, where you can add cost for the screens.
There is currently no way to show customers the difference in impact of two versions of the same improvement. The best way to do it is to set up the improvement one way, print the Detailed Improvement Table (Wizard>Packages>Packages and Reports>Detailed…) by navigating to it and hitting Ctrl+P, then set the other specification and print another copy. Or print two versions of the relevant report page. You can print single report pages by opening the report generator (Ctrl+R) and hovering over a page preview, then selecting the print icon.