It looks like I am wrong about the available powertrains on the SS and it is the RS that gives customers the option to select how it is configured.
" The entry-level RS still comes with front-wheel drive from the low-power motor, but it gets the medium-size battery, and it costs $51,995. However, you can select a large (bigger than the medium-size) battery pack model that comes standard with rear-wheel drive. The rear-drive RS gets a different, more powerful motor than the front-drive Blazer EV does. Additionally, you can spec the RS trim with the dual-motor all-wheel-drive setup that is optional on the 2LT. Maximum range for the RS is 320 miles, making it the trim with the theoretical longest range. Unfortunately, we don’t yet have output figures for these various trims, but expect the Blazer EV to follow a similar pattern as other EVs. The all-wheel-drive dual-motor versions will have the most power and best acceleration, while the single-motor versions offer up the maximum amount of range with their respective battery packs. If you spec the “comfort and convenience” packages on the RS or 2LT, you unlock the 1,500-pound towing capacity that the Blazer EV offers, but it’s only available on these models."