If the snowplow, helicopter, and the tractor-trailer parent let go. They realize they can handle the pain, the loss of control, the grief and live through that; which they will. It’s not fun, but they live through it. What happens is that the child has been independent, you are now separated, and you can come back to the picture with a friend to friend relationship.
You would never order around your friends or expect them to listen to your every command. You wouldn’t do that because it’s invasive and that sets you up for a problem. It’s the same with your adult child. If you are invasive with your child, they may not be telling you, or they may not even be conscious of it, but this causes resentment. Invading their space and treating them like a child would ruin any friendship. It’s going to ruin your relationship with your child. That’s a little gauge you can use to realize if you’ve lost your way.
Parents forget that an adult child can leave for good and never talk to them again. It’s a huge risk you’re taking by not feeling and allowing this separation to happen. Not going through these feelings can cause your child to leave and not deal with you at all, or worse deal with you but be gritting their teeth and hating every moment of it. Is that really the type of relationship you want to have?