For example. When I make a box of sheet metal, I want the lid flat to be 1/2" outside the box edges, then match the bends to the inside of the box. I don't think there is a way to do this in sync. By working that way, I know the flat pattern size is a nominal dimension and that the lid will be bent right no matter what gage is used for both the lid or the body.
The box size and gage are both edited for every copy of the file. I have 100's of copies.
The problem with Sync and sheet metal in general is that the flat is tied to the bend. I want them loose to eash other and tied to the nominal deimension of the box and the gages.
Another way to say this is. I want control of the flat pattern size directly from the model overall dimenions. Then the flange lengths are a result of the flat size and gages. Flat pattern sizes can't be directly controlled in Sync.