Baconator is the oracle who foretells the release of every exam. He hears things in the wind.
As to your other question. The release date is fluid. It's whenever NCESS has completed their internal processes.
The scores are known pretty fast. It's a scantron after all. It's the pass/fail threshold that changes and most of the exam cut scores are probably known by now too. It's the new tests which currently don't have a cut score that delay it. A meeting of SMEs is needed to determine the cut score, and a bunch of things need to happen before they can have that meeting - probably about 3 weeks worth of stuff that has been discussed ad naseum in other posts. If the three upcoming meetings are what I think, then these are what determine the "cut score" for that exam going forward. I am grossly oversimplifying it.
NCESS won't release the scores to the states on an exam by exam basis. All PPE exams' scores and pass/fails are released to the respective states at the same time. CBT doesn't apply here.
The NCEES designed exams usually schedule their cut score meetings in the first 30 days. Its the smaller non-NCEES exams that (for whatever reason) tend not to be scheduled in the first 30 days. For example: Nuclear held up the release for Oct 2013, Petro in Oct 2014, nothing held up Oct 2017 because there weren't any new tests that cycle.
I don't know why the cut score meetings were scheduled so late this cycle. My guess is that they looked at when the meetings were scheduled last year and planned for the same-ish dates this year. But nobody realized that the test was conducted a week earlier than in 2017 and didn't make the adjustment.
Why 2-4 business days? That's just a trend from past observations. And it passes the sniff test. We're all engineers here so most of us had to get major deliverables checked and approved by management before they go out to the "customer". At 10,000 ft your experience probably looks something like this hypothetical scenario:
End of Day 0: The group finishes their meeting. They write up their conclusions as appropriate and transmit it to NCESS HQ it by COB.
Day 1: 8:00. NCESS HQ opens for the day, checks their email, receives the report and criteria. Worker bees apply the criteria to the last of the exams and run the examinee reports. Let's say this takes a couple hours.
Day 1: 10:00 NCESS QA manually checks the reports against expected results. A statistically significant number is checked. Let's say this, plus documentation takes the rest of the day. If an error is found, figure it out and fix it - maybe that adds a day.
Day 2 (-4?): The examinee reports, QA checks, and bunch of other things I am ignorant about, start making their way through the concurrence chain for release. Gotta get signatures from various managers, lawyers, execs, etc. , maybe some of this happens on day 1. And if someone is out for the day (sick, vacation, travel, ?, etc) then it can get delayed until that person can sign off. Eventually the big boss approves release. Maybe this takes a couple hours, maybe it takes a few days.
--There could be something else going on internally that I don't know about--
Day 2,3,4?, Once final approval is given, then the scores get sent out to the states. The process of starting to send it out to the states seems (but not always) to start a few hours after regular opening business hours. So lets call this a two hour process.
The results go out to the piece mail. (Non-Canada) International results seems to get released immediately and all at the same time. Don't ask me why. Then its sent out to 54 US jurisdictions but at different times on different days. This spreading out of the US results is intentional for reasons unknown to me.
