What did I mention that’s not part of the open source definition? Btw, I’m using this one, and only mentioned redistribution, which is the first one:
The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.
The next big part is able derivative works, which is also not allowed as part of the Unreal license AFAIK.
You’re confusing “free” (as in freedom) with open-source.
ETA: you’re correct that Unreal is source available, but a lot of what you listed is not required to be open source.
What did I mention that’s not part of the open source definition? Btw, I’m using this one, and only mentioned redistribution, which is the first one:
The next big part is able derivative works, which is also not allowed as part of the Unreal license AFAIK.