thx mate. i managed to install latest official 3.7.0 twrp and decrypt worked!Yes you can dirty flash an older ROM without decrypting data, just remember to clear cache before booting.
However you can use an unoffical version of TWRP that does support A12 decryption:
but now was the curious part: after decrypt i dirty flashed june release over october one and got rescue party! unsure of what to do i simply flashed october again and got up again, sadly with transmission broken.