Currently, there isn’t the ability to add new options to the Capping & Flashing Tool.
However, there are two ways to achieve a similar result, which I’ve listed below.
Manually draw the profile, then use the BIM Tool to add the estimation information to the capping. When you do this, make sure the UOM is set to Lineal & you enter the length of the object. Note: If the length is changed this value will also need to be changed to reflect it.
[PlusDesignBuild option only] Manually draw the profile & make it a group, then use the Custom Estimation Tool to apply the correct material to it. Note: The name of the material can be adjusted within the takeoff or a new material can be created within the dialog.