daz studio 220.127.116.11, blender 3.0, diffeomorphic 1.6.1.0806
Personally I don't like too much physics simulations because they may be hard to control. Also I do not like complex setups I want things easy, so most tutorials on simulation don't meet my personal taste. For these reasons I prefer to use spring bones for bouncing effects, that are easy to setup and control and usually fit most purposes. See below for an explanation.
That said, since there's some request for "realistic" breasts with bouncing and collision effects, I decided to dig in for the fun and after some tests I believe I got something decent enough. Beware I'm not a simulation expert at all, so I'm sure things can be improved. Credits to Aneesh Arts for the explanation of soft bodies in blender.
The following setup is based on the blender softbody modifier, it uses the pectoral bones and weight maps from the genesis figures, and provides both breasts bouncing and collision effects. This setup is also easy enough and can be automated by the plugin. So let's start.