@eric Thanks for pointing out to me the option of transferring from DWB to Extender, I didn't know that. Nice for a future website that needs such a transfer :).
By the way, those old options were imported not from old Extender Options, but by importing a DWB backup using Extender (which I now understand is not the way to go). Extender has never been used before on this website, only DWB.
Anyway, the site I made with DWB resembled the Genesis Sample theme so much that I decided to switch to that theme which is fully Gutenberg optimized instead of using DWB. DWB still needs this optimizing I think.