Regarding my LED OCD board:
As mentioned, it only controls the lamp matrix. The shield inserts on STTNG are GI under inserts, which is uncommon. An LED OCD board will not help in this case, nor will the WPC patch. I've done some work on a prototype for GI, but it still has a long way to go.
Quoted from sturner:
He doesn't have any for WPC at the moment, but if enough people pre-order/request them on his site, he'll be making them. I'd put in for one and we'll be one person closer to getting these out there again.
I am already in the process of building WPC kits, and they should be available mid-September.
Back on topic, the mentioned "Allow Dim Illumination" is the only way without extensive mods to eliminate the GI flicker completely. Even with incandescent bulbs, I can see some underlying flicker when they dim. It's much more pronounced with LEDs. As flugs mentioned, there are special LED bulbs available that try to smooth this out, but I don't have direct experience with them.