ya i think it slowed down due to change in departments and more checks.The key takeaway for me from this is that sooner or later they would put an independent/civilian oversight over CBSA, similar to how CSIS was born out of RCMP. And yes maybe that prompted longer time in general for security checks starting mid-year 2018, both to start and to finish, as the notes from the CBSA president was sent to the Public Safety ministry only "early 2018".
As for whether that is related to my case, I've refrained from speculating too much for my own good.
as for my case it appears they have not even started security.