wpgraft never reads Beaver Builder’s data. There is no exporter and no importer anywhere in this. It reads the page as your browser rendered it: the real elements and the real computed styles on each one, at every width you ask for. It then builds that as Figma layers: frames, text, vectors and image fills, with auto layout wherever the page was genuinely laid out in rows and columns. Nothing that arrives depends on Beaver Builder still being there.
Your Beaver Builder page stays exactly where it is: nothing is exported from Beaver Builder and nothing there changes. What you get is the page as it looks today, as layers in your Figma file, to redesign, to hand to a client for review, or to keep as the design record a built site so often no longer has.