Blueprints are considered intellectual property in the same sense scripted code is.
The fact that Blueprints are directly convertible to C++ further enforces this.
You’re entitled to make your own changes for to suit the purposes you require but you cannot claim original authorship for works you have altered unless it is entirely trans-formative, an example would be to post reviews using footage which is protected under fair use as it is a form of criticism.
What you cannot do is create direct derivatives from existing work and claim you went through the discovery and intellectual processes required when creating original works.
