How do I know my TRL evaluation is accurate?

The Technology Readiness Levels (TRL) are pretty standard fare for most deeptech investors to ask about. We've self evaluated our TRL, but how do I know I'm being fair and accurate in my assessment? I think it's not uncommon for a startup to overestimate where we are at - is there an independent evaluation? How can we know for sure we've defined our TRL accurately? Any tools or quizzes to help us double check our gut on TRL?