1Password Opvault

I've somehow managed to forget my 1Password master password - I have a rough idea of the format of it, but i just cannot find the right setup.  I've read all the posts on 1Password cracking using hashcat, and they all seem to refer to the old vault design rather than the new OpVault.  Does anyone have experience with the new vault?

I'm desperate to get back in, so will be looking at this over the next couple of days.  The paper on the opvault format is not a particularly light read though https://support.1password.com/opvault-design/