As part of my FL trip, I got to spend time with Alex, Brent, and Chris (visiting from MN I think) the last couple days.
One thing we discussed was whether there was actually a FL 686/FL 694 concurrency, and we determined that there was not based on GIS. (presuming that the frontage roads are just considered as ramps to/from FL 694 and US 92)
I think that FL 686 should just be truncated to FL 694 in the HB, and that nothing else here is necessary.