Olympia Fields North has the same situation as Harbor Pointe with the 6th and 7th holes. Groups will often play their tee shot on 6, walk sideways to the 7th tee and hit a drive, finish play on the 6th and then walk off the back of the 6th to their drives in the 7th fairway. Seems to work pretty well getting groups through that part of the course on a busy weekend morning.
As for the flow on Pac Dunes, I find its more of a group by group situation than anything having to do with the course. You'll end up waiting when the group in front of you slows down, which can happen pretty easily on a few holes. So if a bunch of stronger players are chasing some weaker players, they are most likely going to wait a bit. There are rounds where it seems like you're waiting every hole, just as there are rounds where it seems like the entire course is moving on pace.
That being said, play does slow down a bit on the par 3's. There can be a wait on 5, 10 and 17. Usually you don't wait much on 11, as the back to back flow means you're pretty much walking on to the tee when the group in front is leaving the green. Maybe its that people tend to take their time on 13 (whether due to difficulty or soaking in the view), but there's never really much of a backup on 14. You can almost guarantee you'll wait on 17, as the short nature of 16 and the difficulty of the 17th often create a delay. There's probably an interesting case study to be done comparing the flow at 16/17 at Pac with 4/5 at Old Mac.
There are also spots on the par 4's where you might have to wait if the wind is blowing in the right direction to make them drivable (6 and 16 particularly). The same applies to 8 at Trails and 16 at Bandon, and sometimes 13 and 14 at Old Mac.