To support better interaction between Product and Project link I will suggest to allow a PDM check out on Released CAD objects from Product to Project... You can then create the new design ideas on the Released Project version and when design is accepted as part of the Send to PDM choose to Revise and make new version in Product.
This will help not to revise in Product before you can do a PDM Checkout... and if change i Project is cancelled no new revision is created i Product.. This will reduce the management of new revision not used in Product.
