It would be nice, when upgrading a ship design if the user had the option of starting with the prior complete design rather than with one that strips out all of the non-eye candy components.

For example, if I'm upgrading the design of my small war ships to use a later generation of lazers, I'd prefer to delete the prior lazers and then add the new ones, rather that have to add the new lazers and readd the engines and any other compents.

For this to work the "Clear" button should be renamed "Clear All" and a "Clear Components" option should be added.

Just a thought.