Any EM-406 WAAS/EGNOS/SBAS successes?

I can’t find any evidence that WAAS works with SiRFStarIII-based receivers, like the EM-406, despite claims and “WAAS-enabled” emblazoned on BT-359Ws. It sees PRN122 easily and PRN120 occasionally, but never collects corrections.

Has anyone seen WAAS working on SiRFStarIII?