At the moment when the AI designs its ships it slaps components on at the default size.
This means that some of the cool ship templates that you make for them are wasted 'cause you can barely see the extra components you added for all the Laser MkV's taped on.
A component size slider (or even just a size modifier in the race's config file) would mean you could adjust the default size so the AI ships don't look like they've been doing steroids.
Or I guess if you really wanted to get into it, it would be nice to have templates incorporate component size planning. For example if you put life support components on a template, then the first and subsequent life support components added by the AI will be in those locations and at that size.