I didn't test how my edits affected gameplay. But I did discover that the game is somewhat erratic in how it treats edits to the DefaultDesignTypes file. When I did some tests, I deleted all the lines and put my own in. Here is what I observed when I started a new game and designed a new ship:
QuickStart with Amon Krie - only new type
Add Existing Amon Krie - default types + new one
Create new race - only new one
Load existing race (the one I just created and saved) - default types + new one
So, make of this what you will. I dunno what it means.
