Changing a Particle Vector Parameter

I have a particle system which I have added as a component to a static mesh. Everything works fine initially. My goal is to change any vector parameter in this particle system on overlap with the static mesh, but I am unable regardless of how many tutorials I follow or how much I have googled.

To my knowledge this is all that should be required:

  1. Change an attribute in Cascade to vector parameter (in this example I will use acceleration)
  2. Change param modes to DPM Direct
  3. Name the parameter (in this example I will call it Accel)
  4. Change the min max values to desired range of possible values
  5. Go to static mesh bp
  6. Get reference to the particle system component
  7. Set vector parameter node in overlap function using a suitable vector, and typing the name Accel

Am I missing something in this process? I have spent so many hours on this but to no avail. The weird thing is I can get any scalar parameter working, but not vector parameters. Any ideas of what I might be missing? I’m using 4.21.1. Thanks for your help!

Blueprints of my setup below: