Have you looked into Gerber or Sign Wizard?
I started with Gerber back in 1996 and never looked back. Of course, I started with a Gerber Edge and a HS15 plus, so I needed to have better capabilities than what other software offered.
Since then, I have kept Gerber Omega current and have purchased Signlab and recently Flexi 7.6. I do lots of design with Corel and Illustrator, but for straight up text and lettering, I stick with Gerber Omega and Flexi. I like being able to open the file back up and altering it and then cutting. I can't do that if I design in Corel or Illustrator. Well, not without having to import/export. More work seems like. Save yourself some headache and buy a proper sign software. I did everything with Gerber for 7 years before buying into the others. You can always upgrade your Gerber or Flexi as well.
I am using Flexi to run my Mimaki and it works great on my other plotters. I'm planning on getting Flexi 8 in the next couple of weeks.