Over the years I have tried several ways to copy parameters from one family to another. I have created solids or reference planes added dimensions and then copied all of that to the clipboard, then pasted to another family, and deleted what was pasted. I have used Dynamo and other add in tools as well. This week I realized you can simply copy the dimension, then paste into the other family. No need to go back and delete everything as nothing will actually paste but the parameter names.