Petrie measured 203 courses but actually counted the last two from a few fragments, he never saw a platform as you illustrate and these last two are very speculative. There's nothing to suggest that this point has any significance, it's just what was left after higher layers had been removed.

Goyon who counts 201 layers left now (as do other writers) doesn't even agree with Petrie's height at this point so your alignment doesn't even exist if he's right.

I can't see anything in your drawing of any significance.