Instantiation of components within component BPs

I’ve seen many similar questions and searched the docs, but I am struggling to make headway, so…

I am trying to create a wire component that does a similar job to the built-in cable component, but without physics. It should have two spline mesh sub-components, and should be able to set the position of these when it receives a call setting desired start and end points for the wire.

(I’ve got this working in a normal blueprint but want to abstract the wire handling to a general component.)

I’ve got the component BP set up as follows, with Wire1 and Wire2 intended to be pre-instanced spline meshes:

I’ve also tried set Wire1 and Wire2 to be spline mesh actors, rather than components.

When accessing these spline mesh actors, they appear to be invalid references (i.e. the spline meshes do not exist).

I know I can get the parent actor to create the spline meshes and hand them over to the wire component, but this seems an ugly way to do it. There is of course no constructor in the component BP. What is the approved way of creating (if necessary) the spline mesh components? Or is there no alternative (via BP) to creating them in the parent BP construct?

Thanks in advance.

For what it’s worth, this is an example of creating the spline mesh components in the parent blueprint and passing it to the component (after this, the properties i.e. start and end point of the component are set). Maybe this is just how it’s got to be?