Back when sheet metal was first introduced into Solid Edge (V. 3.5) we did not have the ability to flatten a bent part directly in the sheet metal environment. I don’t recall what version allowed us to flatten sheet metal in the same file, but it was a few versions past sheet metal introduction. You had to insert part copy the formed part into another template while flattening it. This technique might be useful to you in your situation. When you insert part copy you have the option to flatten it and to select a plane to flatten it against.
This creates a separate file, however, the second file is linked to the original, formed part and will update if the formed part changes. You could then go into this flattenedinserted part copy and add dummy features as required to create the flat pattern you need to see. Then you would use the second part to display your flat pattern. When you open the inert part copied part you can select if you want it to update automatically in the future or specifiy how you want it to behave in the future.
As I said, there are two files, but the second file is linked so you don't need to worry about using variables to tie files together.
Process is as follows:
Create a formed sheet metal part as you would do normally.
Open a new template like you are going to start a new part and select insert part copy from the clipboard tab. When the window opens select the formed .psm file. A second window opens where you can check the “Flatten part” option and select a plane to flatten it against. You can insert it into either a .par or .psm template. Not sure if one or the other would be beneficial to you. I seem to recall always inserting the flattened part into a .par file so I knew which was which, but it has been a long time since I used it.
Save the file and call it 123-4567_Flat.psm/par, or whatever works for your naming convention.
Add dummy features to make it look correct as required.
Use the _Flat file for your drawing flat pattern and your original .psm file for the formed version.
Manager of Engineering - Highwall Miners Caterpillar Global Mining LLC Houston, PA