Whatever the fine or penalty may be, is usually not relevant to the tenant seeking to defend a tenancy against either a nonpayment summary proceeding or a holdover summary proceeding.
The reason is fairly simple and also hard to believe. First, a landlord that fails to maintain a current and effective registration statement, may correct the failure in less than one day by "filing" a new registration statement and by paying the proper fee. No fine or penalty will be added to the basic charge for filing the new registration statement. Second, although the court rules and the underlying statute are clear, that an owner may not maintain a nonpayment summary proceeding in the absence of a current registration and an affirmative statement in the petition that the landlord is "in compliance" with the registration requirement and designated a registered managing agent, the courts allow a landlord caught in a lie to bail itself out and continue with the case, as long as the owner files a current and effective registration before the judge has to decide the case. Third, in the case of holdover proceedings, many courts now simply ignore the registration mandate of the statute if the landlord only sues for a judgment for possession and not for a money judgment.
That does not mean that a tenant should not raise the defense in the Answer to the petition that the building is not properly and currently registered, and does not mean that a tenant should not make a motion to dismiss for failing to state a cause of action by reason of the landlord's failure to comply with the statute and the court rules. A tenant never knows when a landlord may be encountered who cannot do the most basic tasks required to keep a case alive.
And in an extreme case, judges may still apply the law as intended.
You could read more about the requirements to maintain a current statement designating a registered managing agent in a multiple dwelling here: