Thanks, I never thought of that so that's definitely what I will try!
I think you do not need a special design. Some people use organza when stitching an FSL design, no reason why you could not add mylar if you wish. However, it might tear along the dense satin outlines, especially when you want to shape the still wet article over a bowl, so handle with care.
I checked there this afternoon along with several other sites but none of them mentioned the use of mylar with the design.