[Jon]

CDSEO will create a canonical link on the ?parameter=X urls so the specific url with this parameter won't be indexed, for this reason typically you wouldn't customize the title for a parameter string. With regard to the title, CDSEO will overwrite anything in the title field as you suspected. To change this you would have to either:

1) Disable CDSEO Product Titles replacement in the CDSEO settings and customize your home.tpl for product titles.

2) Create a filter that runs after CDSEO to replace the title tag again to prepend the parameter.

3) Have a customization done by us to CDSEO (since the portions of the module needed to edit are encrypted).