Following up on the CI seat assignments. Here is what I have learned. This applies to non-status pax.

1) Many seats are shown as blocked in Expert Flyer. These seats will eventually open for assignment. The question is when and the answer may depend on your fare class and status. Our fare classes were X and L (IIRC). By online check-in IIRC more of the non-exit row seats were available for assignment even to us (but some became available earlier).

2) According to multiple CI agents the lower your fare class the more restricted you are in what seats can be assigned in advance. The higher the fare class the further forward in the plane seats can be assigned in advance. Our tickets were class X or L, IIRC, and booked 3 weeks out. Some agents claimed no advance seat selection was available on these tickets but one agent did unblock seats together in the back of the plane for us in advance on flights where the load was light (3 out of 4 segments).

3) T-72: Golden Time! CI Will unblock a few seats further forward for assignment at T-72 (plus a couple of minutes wait) from departure of each flight segment. I missed this window on our first flight and even though I now had the ability to assign seats the only seats available to assign on our fare class at the time I checked the first segment at around T-60 were singles, not together, but I was able to get two aisles and a middle in separate rows which was as good as looked like it was going to get -- ***BUT*** -- after assigning the 3 seats (I previously had told the agent not to assign seats for this segment) I checked again to be sure the seat assignments stuck and imagine my surprise when I see CI has now opened (unblocked) a row of 3 seats (46ABC) towards the front of coach -- score!!! I moved to those seats. The important takeaway here is CI has some dynamic seat unblocking going on after T-72 and the process of assigning 3 seats, reducing the unblocked seat count by 3, caused CI's system to automatically unblock 3 new seats for assignment which were together. So if there are a lot of blocked seats and only middles to assign and you are outside T-72 I would say do not have agents assign seats for that flight and at T-72 (plus a minute or two) when you see a couple of seats free up assign your seats and then re-check to see if new seats have opened.

4) Golden Time may not be exactly T-72. A couple of segments where I moved seats when the map opened up some seats at exactly T-72 (plus a minute or two), after checking the seat assignments did not stick and we were still in the old seats. In addition, the prime seats I had just assigned were now showing as occupied which I at first assumed meant someone else had grabbed them. Being obsessive I kept checking and after 15-25 minutes the prime seats showed available again which I assume meant that the system had reserved them for assignment (by us) but for some reason the quirky CI system was not able to actually assign them immediately and they went into limbo for 15-25 minutes before returning to inventory at which time I was able to assign them with no issue (online). I saw this behavior on multiple flight segments so it was not a one-time glitch.

5) The path to the online seat assignment page was not clearly identified. I had to wade through a link to something like "Other Services" to get to the link to the page for online seat assignments.

Hopefully this information will help someone.