Let us give Diagran a chance...
Diagran, this is what I mean by not giving a concrete example:
Let me give you something to work with public keys through +, - only, it's best to use key subtracter.
First select a range and do subtractions in bulk, then pick one of the offsets and perform the same subtraction on it, then pick one of the second offsets and add it to your original target, if you see the distance between your original target and second offset was added to your original target, it means the second offset is not -n, but if you see the distance was subtracted after trying to do addition, it means the 2nd offset is -n, which indicates your second attempt at bulk subtraction, subtracted a larger number than your original key.
Now since you have your ranges saved, you can conclude the size of your target.
Ok, so in trying to follow you:
My target public key is: 033c4a45cbd643ff97d77f41ea37e843648d50fd894b864b0d52febc62f6454f7c
I ran it through keysubtracter, and selected the first offset: 038a9d2ee7775961943a32840dc7c444eae15a4e2a5e211bda0ae586bcae54e289
and ran that first offset back through keysubtracter.
Next, I selected an offset in the second file and added it to my original target public key:
023d659ede74c20f96b7d17eb93b978ea419be26e598e04eaf57e1e05bb097869f + 033c4a45cbd643ff97d77f41ea37e843648d50fd894b864b0d52febc62f6454f7c = 032bc14141590d389d8926fc02b664df28a44806d94d6dd7852f802fa2423f57ff
Now, when I searched through both files, 032bc14141590d389d8926fc02b664df28a44806d94d6dd7852f802fa2423f57ff was not there. So how am I to know the distance between the second offset pubkey and original target pubkey based on adding the two above?
Explain it to the people. Step by step with examples that can be verified.