I don't know of any such module which specifically allows you to switch characters mid-adventure (with the exception of the mini-adventures for L1-2 characters). There is however, a rule in AL that if you break up a multi-part adventure into multiple sessions, the DM should award XP/GP at the end of each session to any character that participates.
As a result, some players may be absent/show up at later sessions, and some players may decide to switch characters between sessions (this is not recommended but there is no rule preventing it). When it comes to the DDAL/EX modules, you don't get the DT/Renown until the end of the adventure.
Likewise, there is a standing rule that if you do break up a module into multiple sessions, a character (not just the player) must be present for the ENTIRE adventure in order to qualify for magic items, DT, and Renown. If they only show up for the end of the adventure, they are considered to have completed the adventure as well.... Meanwhile if you show up for the first session, you are considered to be part-way through the adventure, but run the risk of leveling out of the module if you don't complete it before reaching a new tier (as softcover adventures do not have the built in level-out protection that HC adventures do).