Community:Constraint dampening
From VRChat Wiki
Constraint dampening or self referencing constraints, is a way to gradually have a constraint follow a source transform instead of snapping to it. This is mainly used on avatars, but can be used in worlds as well. Main constraint types used are Parent, Position, Rotation, and Scale constraints.
Setup
To setup add the Gameobject that the constraint is on to one of the sources for your constraint, and have its weight set to 1. The other sources will be what you want the constraint to move towards. You can adjust the speed of the constraint by changing the weight of the other sources. Higher values is faster, and lower values is slower.