Can you play reactions while the chain is resolving, or does the chain resolve all at once?

Ruling: Yes, there is a pause after each item on the chain resolves where both players can play more reactions and must pass again before the next item resolves.

Sequence:

• Each step of the chain gets resolved in sequence from last to first played
• After something on the chain resolves, both players are given priority to add more items to the chain
• Both players must pass before the next item resolves
• This continues until the entire chain is resolved

Nuances:

• You can shortcut the resolution if there's nothing special going on, but if you want to cut in at a specific point just say so and make it clear
• When an item is added to the chain, the player who added it always gets priority before the other player
• The player who has priority keeps it as long as they decide to pass