To be as safe as possible you should make sure the 3rd parties are dispersed across the globe in various different jurisdictions preferably non communist countries and make sure you never reveal who these people are to anyone for any reason. Make sure they know not to approve any transactions when you’re under duress no matter the consequences.
It makes it so even if you’re detained, kidnapped, or otherwise being pressured to do something with your funds there is no possibility of you being able to comply without cooperation from the 3rd parties who need to sign off on transactions for funds to move.
Yes and no depending on your definition of safe in this context and why someone is trying to do something with your funds (such as a hacker) or compel you to do something with your funds (such as governments or criminals) against your will. What this will do (when done properly) is prevent you from losing your funds against your will at least for a time.
Until the technology exists to detect duress when unlocking encrypted files I currently know of no way to achieve this level of protection without trusting 3rd parties (other humans) will execute your wishes in setups similar to this.