I agree that there probably is abig backlog but it's Not always the case for eligibility.Practically speaking, Eligibility assessment shouldn't take more than 1 hour per application to verify and pass, it's really simple and straight forward for Express Entry since documents format are already disclosed under Regulation 10 and is therefore easier for you to adhere to and for them to review.
However due to the backlog in GCMS, your file will stay untouched for pretty much 99% of the time till someone pick it up and finish it in no time.
As for security, it really depends on your background declaration but for the most part many on this forum have had this section completed in few days to few weeks after eligibility was recommended passed by the case analyst.
Regards
Sometimes they need to verify that document submitted are genuine and not fraudulent. Alternatively not all applicants are able to submit documents in fixed format because of tyranny of HR department of the company they work.
Just providing and alternate viewpoint
By the way @blessed99 last I heard in August first week was eligibility: Review Required. And last update in file was as of March. You are not alone.