If using a municipal ID as primary identification to open a new account for an undocumented immigrant who resides in the U.S. and does not have a taxpayer identification number, can this same ID also be used as a form of "Other ID" on a CTR since it evidences their U.S. residence?

We do not currently accept municipal IDs as primary but wanted to know in the event we ever did, what domino effect it may have on other reporting and recordkeeping requirements.

You've already figured it out yourself; i.e. whatever ID you accept for account opening, you have no choice but to accept for filing a CTR because they probably don't have anything better. If you accept a matricula to open an account, they you accept it for a CTR. If you accept a municipal ID to open an account, then you accept it for a CTR. If you accept a library card...

The CTR instructions list acceptable ID. However, they also indicate that the bank may accept identification that it would accept accept if cashing a check for a non customer. Your bank decides what is acceptable, but they do expect you to be consistent.

Acceptable forms of identification include driver’s license, military or military/dependent identification card, passport, state issued identification card, foreign cedula card, non-resident alien identification card, or any other identification document which contains name and preferably address and a photograph and is normally acceptable by financial institutions as a means of identification when cashing checks for persons other than established customers.

Pages 48 & 49, March 2015 version of CTR Instructions.