You do not need the exclusive version if you are a hobbyist making stickers on a desktop Cricut. You absolutely the eCut for CorelDRAW exclusive version if:
In the context of eCut and CorelDRAW, "Solid Piece" usually refers to a specific function within the plugin designed to: ecut for coreldraw exclusive
In the fast-paced world of sign-making and CNC production, eCut for CorelDRAW You do not need the exclusive version if