The 3.5/9 sources are a complete non-issue has Hyperion has sofar failed to provide any evidence that they have even asked/complained about it, meaning they have (silently) accepted the status-quo on this matter.
The complaint is right in Hyperion's counterclaim where they state they had to contract the original developers themselves.
The developers created their own equivalent or superior versions of the added features of 3.5/3.9 under new contracts for OS4.
To say that Hyperion never complained is naive. Hyperion never complained "publicly" - that I can agree with.