I hear ya…. Your Plumb Bob idea works great.  If you look closely the Fore Mast is not Plumb. Using this method I did tighten up the port side shrouds and brought the mast up straighter. Slight adjustment over the eye ball 👁️.  Rake can be measured as well. 🤪   Depends how much you want to “worry” about it and will it change as the model ages (probably). LOL 😆