Are they using the IP? Or are they using something very similar, along the lines of software developed by the competition who the courts determined weren't infringing.

If they've previously acknowledged that it's the SFT software, apologies, the memory isn't what it used to be. Otherwise, the assumption that they are seems to be erroneous.

A few weeks ago, I posted to Mark Kay a link to open source versions of the same, or similar, software and asked him if they were all infringing. His response was that he was unaware, but, regardless, that SFT patents cover a tight range of IP - and that tells you all you need to know about the ongoing situation.

That's why it was imperative to sell the company a couple of years ago, as originally hoped. Because the value of the patents has been decreasing as more companies develop and market "similars".