How do we make the Plan Type "read only" via Visual Builder?

Summary:

We need to make the Plan Type "read only" when creating a new Succession Plan using Visual Builder. We only build Succession Plans off of Position in our organization so we don't want the other options available to use. We tried to inactivate these lookup values via configuration, but they are locked down as delivered items.

We were able to do this in RUX via Page Composer but it doesn't seem like we can do this via Business Rules in VB

Content (please ensure you mask any confidential information):

RUX example

You can see the Plan Type is locked down