Setting material parameter collection from construction script?

Hey all!

I’m trying to update a Vector Parameter in a Material Parameter Collection inside of the construction script. I could have sworn I had done this before, but now that I’m trying I think I’m doing it wrong.

Whats the best way to update a parameter in a MPC from the construction script?

Here’s what I have now:

Right now I tried to put the update on a bool check, that would just turn off after updating. But it doesn’t seem to work. It does update the Color variable however.

This blueprint is basically empty except for a static mesh and this code.

Thanks!