So after reading what you said and looking at the angles of my blocks, here is what I think.
Please tell me if my thinking is off.
Blocks listed in order of largest angle to flat.
27.5
30.0
32.5
35.0
37.5 (flat)

So if I flip, they should add 2.5 degrees the other way?

37.5 (flat)
40.0
42.5
45.0
47.5

Does the X20 have any built in timing advance, or is the indicated 30 on the block give a true 30deg timing advance.

Sorry about all the questions but I am new to brushless motors..