FreeSSM is a free and easy to use diagnostic and adjustment tool for SUBARU vehicles. It provides access to the engine and transmission control units of the models Legacy/Liberty, Outback, Baja, Impreza, Forester and Tribeca (not before MY1999). 1.2.5 version is the latest. Possible to use the FREESSM software with VXDIAG VCX SE?
The answer is NO. The best cable for FreeSSM is the cheap $10-$20 VAG-COM KKL 409.1 OBD2 USB cable. It is a cheap cable with FTDI chip.
VXDIAG VCX SE does not work with the FreeSSM software. VCX SE only works with SSM3 and SSM4 software. vag-com is not going to work SSM3/SSM4 software. SSM requires J2534 standard compliant adapter. vxdiag is j2523 compliant – vxdiag can be used instead of openport cable. Vxdiag vcx se Subaru works well with ssm3 and ssm4 the vcx se also has a wired cable you can use.
Check: FreeSSM vs SSM3
Neither FreeSSM nor Romraider will connect to the modules in a 2021 Subarus. only some earlier models are supported.
So you have better keep both VXDIAG SSM3/SSM4 and FreeSSM.