I used Casmate for many many years, although only for a plotter. I did purchase Flexi at a very reasonable price (considering the list price anyway) when Amiable bought out Scanvec... but I continued to use Casmate for several more years, however I finally made the jump (& Fred's suggestion) & have never looked back.
There are two other things I am somewhat familiar with that may be of use here is that another nearby signshop also used Casmate when they bought a CNC router, and I would supply him the .scv files for cut letters etc.
I'm not sure if the program was really used to "run the router" or if it was just used to create a compatible file format to send to the router. Since Flexi can read .scv files, I presume it can also export Flexi files, or "save as" an .scv format, so you might ask him if creating .scv files helps him, or running Casmate is still required. This is mentioned simply because there might be easier, or more numerous, solutions if the file format is the only missing link.
By the way, W98 compatibility doesn't work with a dongle installation version of Casmate, because it is an 8 bit program. Regarding the legal comment above, I am in agreement & have chosen to believe that circumventing the dongle is permissible in this case, because my rightful licensed use of the program is hindered by a dongle they are no longer available to support. I never resolved the XP issue, but I know several people have. (for vinyl plotter work anyway)
