Personally, I'd like to have the Capital Ship cutscene appear for the first time you build a Battleship *or bigger*... I never knew the thing existed until a few games ago when I accidentally built a BS... already had a few dozen dreads by then, so the cutscene didn't really fit very well
Personally I want to see a little "planet blowing up" movie every time I use the Terror Star, like MOO2 had with the Stellar Converter. If you got sick of it, you could skip it... but I never did
You wouldn't be able to put in the first time event code though. I think that this is on my list, and I will make note of adjusting it so that if you happen to build a bigger ship than a battleship first, it'll play the cutscene.