Heh, for reference, I just discovered another workaround that works great for me. RMB(Content Browser) > Blueprint Class [Actor]
This will bring up a component editor where the + Add Component] dropdown gives you access to all the /place actors\ options in the main window.
TBH, I think i prefer working this way, as opposed to dragging in toplevel actors, as it forces you to immediately group together all the primitive actors you want logically and up front. ie, a light rig, cinema camera setup with a backdrop (stage), your aggregate primitive subjects etc… kind of enforcing a logical world outline out of the gates, as opposed to dragging in actors, organising them in folders, grouping them, and ultimately Toolbar | Blueprint > Convert Selection to blueprint Class anyway.
Then this /place actors\ segfault can be avoided by selecting this new BP actor in the content browser and RMB(viewport) > to drop it in the scene.
Moreover, the individual components can be edited (affine repo) once in the viewport to further customise the instance, where any newly instantiated BP actors continue to come in with the defaults. Nicely analogous to HDAs for me. Houdini+Unreal+Python+Linux 4 Life!