No. The construction script in c++ is an tree attached to the CDO for that class. It holds descriptions of the subobjects to be created during construction. They are using the term in two different ways. In c++ it’s the tree object. On blueprints it’s working during the actual construction.
In the end we took apart the bp editor and traced everything back to the CDO in code. I’m not at my system or I’d send you the code to actually add a dynamic component.
https://answers.unrealengine.com/questions/216910/calling-construction-script-through-c.html
Another method that was far more tolerant for us in the end was to create a custom details panel that listed the added weapons and provided the interface for the weapon placement without them showing in the component panel at all. It was much easier to put in place and still allowed us to use OnConstruction like normal expectations by looping through the stored data and creating the components when the script ran. But they don’t show in the components panel and we didn’t use transform widget which may be a problem for you.