>>2578210So do you use an Epson or a dslr rig to scan?
If you have a dslr and macro option, get a sheet of opal acrylic, a very large cheap step up/down ring and a backlight. Use the ring to hold the film flat to the acrylic.
If you use the v550, flatten your film by placing it inside a book inside negative sleeves and add a butt ton of weight overnight before putting it in the holder. If it still has a slight curve, flip the film over. Be aware it may not all be in focus. The other option is get a non Newtonhill glass holder from better scanning.