@Ram you didn’t get the idea nor the reply by Epic rep.
You have full source. Epic would have to pay an extra bunch to the respective owners to get middleware technologies like scaleform and so on (not necessarily) for every deal.
Anyway without implementing those you users can choose to implement them yourselves or not plus get a license with those “middleware”.
Epic tries to give you new technologies and such but it’s 1 thing to implement a technology (For example PBR or a custom HLSL shader etc) and it’s another thing to implement another companies tool.
PS: There are things under Innovation license that are public for everyone and then there are those private technologies or tools that companies hold full rights.
PS2: R&D is a hard work don’t expect them to jump at your bidding because you pay, They have their own agenda which they should follow if you would like to keep receiving proper and crucial updates.