README:

For this mod to work correctly, it NEEDS SBX 2.5e installed to avoid skin texture issues.
The reason I'm sharing a cf_base.unity3d file is because I modified the game's skeleton, I added some custom bones.
Mine is based on SBX 2.5e.

These bones are responsible for the movement of the nipples chain. Without the modification to the skeleton, the chains
will appear glued to the floor, or the game might just crash.

If you decide to uninstall it later for whatever reason, make sure to restore the cf_base file from the folder cf_base_backup,
restore your own, or just get it from the SBX 2.5e MEGA file.

No other modifications to any other bones have been made.

THE CHAIN LOOKS STRETCHED:
This is a big limitation I had to deal with, since Unity 5.3.5 doesn't have constraints. So the middle bones are separate,
and there's nothing to tell them they should stay together. Redundant armatures also can't be made (as in a circle, or connecting
a single chain to both nipple bones).

The best you can do if yours looks extremely deformed is use the Additional Bone Modifier mod (it depends a lot on breasts size, distance, nipple size, etc):
http://www.hongfire.com/forum/forum/hentai-lair/hf-modding-translation/honey-select-mods/5719122-honey-select-additional-bone-modifier-v0-7-4-update-2017-06-16

And play around with the following bones (read Additional Bone Modifier's guide to add custom bones to the text files):
cf_J_nipchain_00_s_L
cf_J_nipchain_00_L
cf_J_nipchain_02_L
cf_J_nipchain_03_L
cf_J_nipchain_04_L
cf_J_nipchain_05_L
cf_J_nipchain_06_L
cf_J_nipchain_07_L
cf_J_nipchain_08_L
cf_J_nipchain_00_s_R
cf_J_nipchain_00_R
cf_J_nipchain_02_R
cf_J_nipchain_03_R
cf_J_nipchain_04_R
cf_J_nipchain_05_R
cf_J_nipchain_06_R
cf_J_nipchain_07_R
cf_J_nipchain_08_R

In the end, it wasn't a perfect solution to do what I wanted to do, but it's close, and it's definitely better than the chain getting
squished by breasts and/or nipples scale. Plus they bounce around, fun stuff.