Without an extender you lose out on agnumday which hurts your recovery also caspar becomes a garnet but you do get the musket negates. If you have an extender there is a different line you can do which both gets you agnumday and allows you to get caspar back into the deck to be summoned off of max(or starfire).

You want 2 open spaces in the main monster zone at the end. 1 for A Bao to return to and then the other free space for the twins. Mutiny in the Sky's gy effect can clear an extra fiend off the board otherwise on your following turn the twins can be used for "free" to return it your hand.

Opening Buio or Mutiny means you can skip Aerial Eater which also saves you needing to make an extra body(make FS lacrima -> Summon LF, LF+Requiem=Necroquip, FS Lacrima + Necroquip = Ceaser, or just summon engraver and skip necroquip) and also means you can follow the 2cc line to get agnumday.

Nibiru: Depends on when dropped. Being Fiendsmith it can still make a board via engraver.

Droll: Combo has 2 draws and 2 adds. The 2 draws are optional. If you skip them the order of the adds are Mutiny -> Musket S/T so you would potentially lose 2 disrupts unless you have another S/T to trigger Caspar on opp turn. If you open mutiny then this can play around droll.

Fuwa/Maxx C: Death. You can droll yourself and just go for standard Twinsmith board. If you hard open mutiny you can still basically FC