I may annoy some people saying this, but it's true. SSP is really just layout sketch technique. It doesn't need a special made up name. There's a reason people ask what SSP is - because it's not really a thing. It's a name looking for relevance. It's just layout sketch. Layout sketch has been around for a long long time as part of the software. It was in the standard SW training material from way back.
And then SW confused things by creating an assembly feature actually called Layout. That feature is different from the assembly based sketch. It's just a really bad idea to give things like LAYOUT and PDM proper names when generic names also exist for something very similar.
Skeleton techniques, as far as I know, started in Pro/E. I don't know anything about that, but I think there is more to it than just a name in Pro.
Layout is really just an intermediate step between top down and bottom up.
Bottom up has no references. Well, the assembly references the part, that's the extent of the references.
Top down (in-context) is where parts reference one another in an assembly. So the reference between part 1 and part 2 contains the assembly file. So each reference in part 2 contains links to part 1 and assembly 1. There is always the danger of creating circular references, or daisy chained references that require multiple passes to get everything rebuilt properly.
Layout is somewhere in between, because the sketch (layout sketch) is at the assembly level, and part 1 and part 2 can reference the sketch in the assembly. Some people make the sketch at the part level, and that removes the circular reference, but can create other problems. I prefer the layout technique over in-context.
The problem with this is that it's kind of a circular reference. The assembly references the part, and then the part references the assembly. This starts to slow things down, and the file references start getting confused.
Whenever you use references like this, you have to make sure that you use a structured logic. Make sure that references always go in one direction. If you have references between the part and the assembly sketch, references between parts can complicate things. If you also have backwards references between part and sketch (part edges or sketches driving sketch elements instead of or in addition to sketch elements driving part edges or sketches), you're looking for trouble. Solidworks is supposed to be able to detect circular references, but it doesn't always get them, and it doesn't ever identify convoluted references that cause looping rebuilds.
Master model is different. It usually skips the assembly reference. You make part 1, and then split it into part 2 and part 3, and then put 2 and 3 back together in an assembly. Master model is best used for 2 reasons: 1) to make a smooth shape in one part that would be difficult to make across multiple parts, also allowing you to centralize change where this is a single shape that affects multiple parts in an assembly 2) to try to compartmentalize rebuild time when you have a very complex exterior and an equally complex interior for a single or multiple parts.
Master model doesn't use an assembly until the end of the process when you have the individual parts made and bring them back together as an assembly. You can use the origin for this, since all the parts share the same origin.
The moral to the story is that it's easy to get yourself into trouble with layout and also with in-context. It is less easy (but still possible) to get yourself into trouble if you use master model (especially if you start combining master model with in-context).
And then you've got the additional complications of combining in-context with 1) configurations 2) underconstrained parts 3) master model. If you do any of these you're asking for trouble. Can they be done? Yes, but mostly by either accident or a really expert knowledge of what you're doing. Anything in between will get you in trouble.
On top of this, you have history. The assembly is non-history based, but parts are history-based. Relations between parts in the assembly ignore history, but master model uses history. This all gets very confusing, and it's the reason people get themselves in a lot of trouble when trying to work in-context. People are afraid of in-context because they don't understand it.
https://dezignstuff.com/why-are-you-so- ... xt-design/
Master model can definitely be controlled with PDM. The master model may not be used in the actual production assembly or drawing, but it is a reference that is recorded in the software. It will probably show up as an in-context relation without an assembly.
I name things appropriately so I can find it. I select mate references from the tree, by name, and not in the visual workspace. If it begins to expand past the vertical capacity of my feature tree, I can cluster meaningful portions of the references into categorical folders. Folders in the SSP should match default assembly folders, for greatest ease. Unless I'm dissecting and altering the SSP, it stays hidden.
Begin with redundancies. For example, I have a plane to determine position (Coincident, Distance) and a second identical plane to determine orientation (Parallel) which usually applies accessibility or clearances to operator handles. Then, I can relocate or flip one without affecting the other and everything else tied to the other. In your drawer example, you seem to begin with the assumption that you will have one knob and it will be centered on the symmetrical plane. What about multiple knobs, or asymmetry, or such? Duplicate the Right Plane with an identical Symmetry Plane and maybe even a third Lateral Knob Plane. If you have Sketch symmetry, that centerline can be tied to the Symmetry Plane within multiple sketches for different purposes.
