Some suggestions and theories

[oshfdk]

Any encryption (except for compression, but here it's very unlikely) is a bijective function preserving orientation (while encoded string "ABC" can be rotated in multiplies of 45deg or even reflected, the 'B' would still be between 'A' and 'C' in the output; otherwise we would have more than 1 encryption/decryption for the same piece of information) between 2 sets of (groups of) symbols, therefore any encrypted text can be cracked by a simple bruteforce.

I'm not sure I understand these statements. There is nothing unusual or anachronistic with having multiple ways to encrypt the same message, as long as the decryption is unique. Most diplomatic ciphers worked this way with letter variants. And homophonic polyphonic ciphers also allow multiple decryptions, with the right one only clear from the context.

Also, any cipher that produces out of order pieces can change ABC to ACB:

For example, I can encode this message:
SUPPOSE I WRITE ALL ODD CHARACTERS FROM THE LEFT TO THE RIGHT AND ALL THE EVEN ONES FROM THE RIGHT TO THE LEFT

by keeping each odd letter and removing each even letter and writing them from the end of the line towards the center:

SPOEIWIEALODCAATR RMTELF OTERGTADALTEEE NSFO H IH OTELFTE H TTGRETMR EONV H L N HI H TTE H OFSECRH D L TR  SPU

I'm not even sure how to analyze this in terms of ABC, it's mostly scrambled. And encoding this on a piece of paper is a breeze, just keep writing one letter at a time taking turns at the beginning and the end of the line.