If I'm understanding correctly, the firmware programs OK, (and you've verified it so), but it's the channel programming which is the issue?
The SSC mods "should" be the same thing in theory, though differ in execution. I actually suggested my mod to RJ as a way people could easily (and reversibly, if desired) mod the SSC to use a pin which was actually compatible with 5V data transmission. That almost got me banned for 'technical talk", but a few days later, RJ suddenly came up with 'his' mod which had people cut traces on the board and run a long 'air wire' for the data transmission. The trace cutting is a bit tedious, as you need to make 100% sure it's severed, but be absolutely sure not to cut any adjacent traces. So if you've cut the traces, might confirm it's 100% cut.
Other things to check:
- Input data wire polarity is correct - I've goofed this once or twice
- SSC is getting power (hub fuse is not blown?) - a real pain because there's no way to tell on the DLA hub
- Swap PIC with known working SSC
- Swap ST485 (transceiver chip) with known working SSC