4.2.2 states that a SWPS can be used as is, without modification, or can be used as a basis with additional information or requirements included by the purchaser/employer, providing the additions don't retract from the original essential variables provided in the SWPS.

4.2.3 says that in order to use a SWPS, the employer has to sign it, and thus accept responsibility for its use. Its about removing any supposed liability from AWS and imposing it on the employer.

AWS created SWPS by requesting and receiving a number of donated qualified WPS from various employers, and compiling similar parameters into a unified SWPS, as a basis to reliably state these parameters have been proven good so many times they can be used without need for further qualification. Then AWS turns around and sells copies to employers who are not capable of writing and or qualifying their own PWPS and WPS.

So, an SWPS will not be signed by the multitude of employers that created it, but will have a place for the purchaser to sign in order to accept responsibility.

SWPS's are either a way for AWS to help employers who are unable to figure out how to qualify their own procedures perform, or attempt to perform, AWS code compliant welding.
or
A way for AWS to begin the process of stating that all WPS for AWS compliant work have to be purchased from AWS, so they can increase revenue and build another Taj Mahall.

Tim