Update #3

[buildmaster5000]

Originally Posted by Alan Anderson

Slip rings are no longer disparaged.

Please pardon my terrible vocabulary, but even after a google search I am still confused by what you mean by this . Are they now leagal??

[Jon Stratis]

Originally Posted by buildmaster5000

Please pardon my terrible vocabulary, but even after a google search I am still confused by what you mean by this . Are they now leagal??

Per the update (see link on OP):

The branch circuit may include intermediate elements such as COTS connectors, splices, COTS flexible/rolling/sliding contacts, and COTS slips rings, as long as the entire electrical pathway is via appropriately gauged conductors.

emphasis mine.