Debugging "dead/removed" widget and its state

I have a WBP that creates a child ListBox and upon Construct event said LB launches an async function from a plugin that is slowly building data array. Upon finishing the execution async function would call OnSuccess and return array or OnFailure.
There is no way to terminate this async request manually strictly from Blueprints side. There is also no way to actually destroy widget/its reference so I resort to fairly primitive trick:

  1. Remove widget from parent
  2. Unbind all events
  3. Call “ClearChildren” on parent again just in case
  4. Set the working variable that holds current created LBox widget to default null variable of same type
  5. Call GC cleanup manually at the end (most likely useless if function still executes)

This achieves the visual effect of what I want - callback “goes into nowhere”. What I want to know is what happens behind the scenes - how can I possibly debug it on a development packaged build (cant use plugin otherwise due to the way it works) and get insight into what happens with these removed previous LBox widgets?