There are allegedly 3 versions (unclear how that relates with the AccessDigital parameter).
FOSS tools for editing .par files are there and here, with an unwrapper and decrypter available for the later versions
Removing the RequiredToPlayV1 value from the InstalledDistro entry should remove the Origin client hard requirement. Some games may still *actually* require to communicate with it to work.
p.s. bonus for cryptography nerds