I’m not familiar with the details of the virtual machine in which blueprints are run, although I’m fairly confident that the performance difference between spawning a blueprint actor or a child actor that derives from it are either minuscule or non-existent (which is the case for C++). So feel free to use either based on what works best for you. Nonetheless, it’s definitely a good idea to be aware of Epic’s best practices and guidelines for blueprint and art assets. Hope that answers your question.