Correct. The CH3SNAS works actually quite much the same as the CH3WNAS.
The ‘easier’ installation you found would indeed work for the CH3SNAS aswell.
The difference would be that you’ll have to kill the currently running version on the CH3SNAS first. (As the port is already in use at that moment)
They can both be fun_plugged and both have a “startup” script you can alter. Easy enough for me. 🙂