> The validity of AmigaOS4.x has been fought in court between AInc. and Hyperion
> and Hyperion came out on top, so if they did not have the legal right before, they
> sure as hell have it now and it is clearly stated in court documents to prove it.

The validity of Amiga Inc's claim of ownership over the AmigaOS 3 copyright (i.e. that Amino/AIW ever owned it) was not tested in that litigation. And it's clear that none of the involved parties strived to do so since a possible finding of non-ownership would have compromised both Amiga Inc. and Hyperion*. So the validity of Hyperion's AmigaOS 4 is based on the non-tested assumption that the AmigaOS 3 copyright is owned by Amiga Inc. To turn that assumption into certainty someone would have to challenge Amiga Inc's claim in court. So far nobody did that.

* While Hyperion challenged the alleged IP transfer from Amino/AIW to KMOS/AID, AIW's ownership of AmigaOS 3 (i.e. transfer to AID was illegal) wouldn't have invalidated Hyperion's right to AmigaOS 4. So for Hyperion it was only essential that either AIW or AID owns AmigaOS 3.