A year end update. I have determined that we could modify Lillooet to be prototypical with all the things described below without lowering the track. We would build a 10 inch high platform for the end of the isle. This would make the effective track level 60 inches and not disrupt Squamish much. I am thinking about this as well.

Currently Lillooet on the Layout is just a staging yard representing things north. I am considering a plan to model Lillooet. It would be over Squamish and 16 inches wide. The clearance from Squamish track level to the bottom of the fascia would be 13 inches which it is now. Thin bench work would allow us to lower the track elevation by 4 inches with the grade taken up going south. with an 8 inch platform the effective track height would be 58 inches. Switching would occur at the north end and at the far south end of the isle which would hopefully not bother Squamish work too much. This would add another yardmaster job that is easier. Duties would be to flip cars, turn trains and switch local industry, which would consist of team track, Esso, shops, ramp, log sort and a large sawmill.
There would be a possible space problem with Squamish. This would take planning and be a lengthy job disrupting ops for a while. I am thinking about it.