Sometimes a built-in type parameter needs to be an instance parameter for certain families, and vice versa. But we can't control this, so please allow us to edit this per family. This has caused us to abandon several built-in parameters in favor of our own shared parameters.
Example: Apparent Load is a built-in parameter for lighting fixtures. But some lighting fixtures have per-instance properties that can change the load. So we can't use Apparent Load - we have our own shared parameter.
Another example: For electrical equipment, Model Number is a type parameter but Max # Breakers is an instance parameter. If a panel has a different number of breaker slots, then it has a different model number, so these two parameters are incompatible with one another. We need to either change Model Number to instance or Max # Breakers to type. Similar for Enclosure - a different enclosure means a different model number.