There are absolutely no indicators showing anything moving for outland apps. Only a handful of PPRs vs what it was before the pandemic. IRCC themselves said FSW waits 21 months on avg now and is expected to wait 36 months this year.
Let me be honest. ALL FSW folks are eligible for Mandemus. ALL of them. ALL of them have been waiting for an unreasonable amount of time. The fact that IRCC says that their processing times for FSW will go to 36 months as more backlogged applications are processed is the proof of it.
I think if ALL FSW folks decide to go for Mandemus, their writs will get backlogged (LOL!) at the court. Unfortunately, there is nothing like a class-action Mandemus as each JR is decided on its own merit (in theory, each petitioner has to tell WHY this delay has been bad for them ).
So yeah, very likely if enough FSW folks go for mandemus, you will end-up in another backlog at the court. Another point : IRCC will argue and courts most likely will grant a 60 days of time to finish. Also, before mandemus, you will have to raise a web-query and ASK specifically to finish processing of your application (demand for performance) with 30 days deadline (standard). So in all you will see 90 days of further time without considering any processing or queing time at the court. I guess, in that much time, your application is likely to be decided in normal course of things.
IRCC is typically processing at a rate of 18K FHS persons per month. If majority of that go to FSW, all 54K should be done by march/april end or so. From what I have seen, the current PPRs are dominated by FSW (as it used to be before pandemic).
So yeah, go ahead with Mandemus. It will make you feel good. Not necessarily speeding up the process of landing but surely keeping you sane.
