Here I've added a Kadee 308 under-the-track uncoupling magnet to the spur:
When I originally laid the dual-gauge track, I decided not to make any provision for magnetic uncoupling, since the HO and HOn3 couplers would be on different centers, and magnets would work only with the one gauge and not the other, depending on how they were positioned. More recently I've come to realize that most of the actual switching and operating I do is on standard gauge, so I decided to go ahead and install magnets on certain spurs aligned for standard gauge operation.
Here is a wider view of the East Terrible area as it stood a week or so ago:
Ballast and ground cover work are under way.