I separated the passenger parts into three parts:
The man standing posture
Chairs have more connection points, up and down left and right......You can connect to more places, you can connect to people who are sitting
The seated person has three connection points, one on each foot, and can be placed in an empty chair or, better yet, in a custom chair
A person in a standing position has four connecting points: head, feet, back, and chest (but not chair).
I have added another test dummy, which you can control!
Forward, backward, spin left and right, but don't jump
Feet will sink into the ground (this should be animated for the reason)
I recommend that this test dummy not connect to anything
Because when you connect anything, the connection points are useless, and they don't connect, so I'm sorry
Of course, you can also make the test dummy 100 times larger, which should be interesting.