New customer feedback on vxdiag Subaru SSM3 multi tool.
The tool works for programming keys! Just make sure you buy a key which is “unlocked” because that is a separate process not supported by SSM. I bought this one on eBay:
To my surprise, vxdiag didn’t even ask for the security immobilizer ID. And process described in SSM3 manual did not work (it says to go into Other Models > Each System Check > Keyless Unit Mode).
In the menu, I chose Other Models > Immobilizer > Generic Scan Tool > VxDiag > Smart key registration. I just had to hold the existing key up to the start button, then do it again with the new key, and voila! It works with both RF buttons and proximity sensing.