So here's my wacky idea. If the starwheel tracks are caused by uncured ink on the print passing under the wheels, then it follows that curing the ink before it passes under the wheels would fix the problem. If environmental humidity is high enough that "more passes" isn't sufficient, then the only solution I can think of is to drop environmental humidity -- at least within the printer.
Easiest way to drop humidity is raise temperature. So, I'm wondering if I can rig a hair dryer or some other device to an air ingress point of the printer to blow warm dry air inside would help. Or, perhaps a small flexible tube could be taped to the printhead carriage to blow warm air across the print as it approaches the starwheels. Or, well, perhaps I could air condition my studio.