Need to dynamically add depencies to a running build Follow

We have a highly data driven build system that triggers configs based on the input params provided.

Because of that we can't use snapshot depencies.

What I was hoping to do in a plug would be to add to the parent build the children it has triggered so it shows up as depenencies in the UI and in the rest data.

But from what I can tell I can't just add to the Dependencies off the build promotion.

runningBuild.getBuildPromotion().getDependencies().add()