Agree that 2030 is a more stable start generating source than any quick servant in the game. However, Jack is the best start generator in the game, it feels like a waste to put a CE that was meant for servants that can't generate start on her.
If you want more stable start gen then why even bother with quick servants in the first place. Just go with 2030 or any servants with passive star gen like Hans, Jeanne, Merlin etc.
Well, the Jack's Best CEs section above listed 2030 as Jack best CE, when she suppose to be the best stargen in the game. There is no reason to put 2030 on a servant that can generate a bunch of stars on her own.
You clearly never played the game. Or at leat never try to utilize quick team. Jack 3 quick cards is distributed in 3 turns. Which means CE like 2030 is to add consistency when none of her quick card or only one of her quick card available. Using passive stargen is difficult if youre not a whale with 3 2030 because the star gathered from the servants you mentioned only give aroud 10 star per turn.
Passive star gen team can be formed even without 2030 all you need is 2 passive star generators (Hans, Liz Caster, Mephistopheles etc ) and a servant with high star weight. I actually found passive star gen team are easier to form compare to Quick team at least in NA due to the lack of cheap Quick star generator.