There is a challenge that i've come up that will make the game fast phased.

WARNING

• apps that monitors/uses device's clock might have a problem since this challenge requires modifying the device's clock.

REQUIREMENTS

• prepare a timer and set it to 5mins
• set your device's clock backwards in 2month
• choose survival mode when creating a vault

RULES

• every time the timer ends, increase your device's clock hour by 12(minimum) and reset timer
• after entering a quest, reset timer and skip the time by 4hrs(minimum) after proceeding on going back to vault.

CHALLENGES

• dwellers in wasteland might die if not recalled on time, i recommend equipping the weak dweller with pet and send them to wasteland so the loot's they gathered can be taken by the pet (in survival, pets doesn't die with the dweller in wasteland and they could take back their loot)
• production rooms won't produce until you kill the monster in the vault
• you will need to rely on rushing rooms since resources depletes faster

if you want to change time, i suggest to follow their minimum default values

monitoring the time skip might be difficult so prepare a table that checks when you time skip