We are not using any of the Action functionality in cost plans and when users click on it, it creates an issue for us. Specifically, the Populate from… options overwrite the Cost Plan data with no option to undo. We would need to disable or hide these options and looking for your help on the same.
As per current design it is not possible to hide those options.
Suggestion is to raise this as an enhancement and details are for how to do it is here.