I haven't kept up with the fonts on the Flexi upgrades over the years, but my first copy was a very affordable "cross-grade" promotion when Amiable bought ScanVec & ended development of Casmate. At that time they offered Casmate Pro users a license for Flexi Pro for $1200, and they promoted the fact of Flexi opening .scv files as well as running all the same original Casmate fonts.
ahhh... so many memories of my Casmate days... I didn't actually use Flexi for 1 or 2 years after buying it. Flew over to Big Island from Maui, to attend an Inspire training workshop, & even after I got a free copy of that, I wouldn't let go of the security blanket of of Casmate...
...but I finally quit hanging on to that, and Windows XP, and have never looked back, figuratively speaking... I do have pretty extensive backups from the last 2 decades, so I've had .scv files to try to restore & convert through Flexi, and it was hit & miss at times. Good luck with your files.