Let’s say I have three cubes in the scene
I select two of them and convert them to blueprint class
Now I want to add the third cube to the blueprint, how would I go about doing that?
If I select the newly created blueprint and the cube than convert again, the result seems to me like a buggy mess since I now have another scene root and the previous meshes have been cleared and their vector moved to the same location. There must be a copy paste method but I cannot find it.
To answer my own question, which was itself a mess and came from a lack of understanding on how UE4 works:
To add a component to an Actor Blueprint one has to use the “Add Component” Button from within the Blueprint, select the desired component, and eventually populate it with an asset.
In this case if one needs to add a mesh to the Actor Blueprint, he/she would need to add a mesh component and then pick the desired mesh for said component.
 
Thanks for the answer future me.
Not a problem past me, it just took some more practice.
