Would it be possible to add an option when in Product Prompt or Subassembly Prompts where you right click on a cell and there is a "Revert to Default Value" option that puts the cell back to the default value or formula for the spec group? Maybe it's ignorance but it seems like it wouldn't be too crazy considering all products come in with those defaults on initial drawing. For reference Fusion360 does a good job of this and has some additional options as well. https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Setting-defaults-for-CAM-operations-in-Fusion-360.html