You have applied some Miter cuts, with the command Miter from the menu Design > Frame, to the Frames of your assembly inserted with Frame Generator.
Now you want to display the angle info of these end treatments in the assembly BOM and Parts List.
When you apply the Miter cuts to the Frames, Inventor creates for each frame, some custom properties named CUTDETAIL1, CUTDETAIL2, etc.
In case you need to display these columns in almost all your assembly BOMs, you can include them, by default, in the BOM of your assembly template.
In order to do that, you open a new assembly selecting your standard template and, after having added the two columns, you save the assembly as template with the command Save As > Save Copy As Template.
In order to display the two columns in the Parts List of the assembly drawing, edit the Parts List after inserting it and add the custom property columns.
Caveat. If you delete the Miter cut of a frame associated to the custom property CUTDETAIL1 and recreate it, the name of the property will be CUTDETAIL3 and the value will not display in the corresponding cell of the CUTDETAIL1 column.