Export Rack Type
If you can't make certain changes directly in the blueprint rack, you can export the rack type to the global catalog and update it there.
Next Steps: From the left navigation menu, navigate to Design > Rack Types and edit the rack type in the global catalog. (Or, if you couldn't export the rack type, create one that meets your new requirements.) Then from the blueprint, Update the rack to use the revised (or new) rack type from the global catalog.