Just plane confused!

[3Putt]

I'm new to TGM and enjoying every minute of this forum. I'm hoping to get some help to get over a rough spot so I don't get bogged down and frustrated too early in the process.

The book is organized in such a way that concepts are revisited multiple times. Often times, these "revisits" don't always seem consistent, or at least I don't leave with the same interpretation each time. One in particular - the inclined plane - I just can't seem to get my head around. Here is a sampling of what I read, and what I perceive as mixed messages:

2-F The full length of the clubshaft remains unwaveringly on the face of this inclined plane - waggle to follow-through

7-6 clubshaft must start its journey on the plane of its address. It may or may not move to other planes as it travels

7-7 ...it is not always possible or advisable to adhere to a single inclined plane classification throughout the entire stroke

10-6b any plane angle shift is very hazardous
immediately followed by 10-7a thru h which documents plane angle shift variations (i guess they can't be that hazardous after all!)

So in these snippets, I get mixed messages - sometimes I read stick on one inclined plane....any shift is hazardous. Other reference rationalize (and even recommend) plane angle shifts. Evidently, I am not reading these in the proper context (after all, TGM has withstood alot greater scrutiny than mine) Would someone care to offer where I have gone wrong on my interpretation?

Thanks