OT-Favorite SE4 Moment!!!

[Master Belisarius]

I think that you don't need something special:
1) The AI must have Stellar Manipulation capabilities.
2) Include the ships into the _AI_Construction_Vehicles.

For example, for my modded races, I have included the construction of a sun destroyer, in the early Infraestructure queue, and I saw both races using these ships very often (in games with all the tech available from the start, or in standard games but after research this tech).