I created the layout sketch in assembly. More to be built-up in the sketch.

Up to now having created some sketches on several planes (created from within layout sketch), I created another plane (Plane-5) and some sketches on this plane.

I need to re-define the Plane-5, but likely no any option is available.

I request someone give me some feed back. Sample file (Solidworks 2020) attached. Thanks.

I have done successfully TOP-DOWN model (for a belt feeder) with a master sketch, please see Figure-4. I thought, using the layout approach. But, it looks like the layout sketch has no use or practical significance. If 3d-place redefine feature is available, it is possible to go further down with design for change concept. In general, Layout concept is harder, I believe.