I have some Walnut & Roble burl that I got from Veneer supply. I do have to flatten them using Super soft 2. The website says that veneer should be used in 4-7 days once it has been flattened. I was hoping to leave the veneer pressed between two platens until I need them. This may be months later. Would the veneer still be flat and soft enough to use? Thanks in advance for your thoughts.