No, all the above are incorrect.
A SDI DMC has one calendar year from the time they sign up for training to complete their DM. This is in the general standards, it is not located under the divemaster standards. If a DMC goes over a year??? Per the general standards, the DMC is required to start from scratch.
In the past, if a DMC went over the time limit; a waiver could be requested by their instructor/shop citing whatever the circumstances….or a secret handshake.
Today, if a DMC goes over a year, but not a year from when they satisfactorily completed the DM test, “Due to COVID, we are allowing DMCs the extra time, but we are requiring them to retake the DM test to 100%, with remediation.”