Can I use the side extensions (part no. 201909) on a KS 60, without the mobile trolley? Can I use the extensions on the ground, or work bench,with extension legs folded?

This is an option, however you must also use the adapter plate (part no. 202056) and the extensions will not be level immediately.

You will need to support the extensions with timber or suitable material to ensure its level. There is the ability to screw a support piece under the extension.