1)I've seen many instances of 4 wire RS485.
2)This differs from RS422 in that multiple devices can share the same transmit pair.
3)Whilst RS485 implies a wire half duplex bus that's not normally the case in practise.
4)Don't believe me? Do a search on the web and you'll find evidence of it.
1) This is balderdash/horsefeathers or whatever.
The fact that a bunch of nincompoops have 'invented' "4 wire 485" does NOT make it 485.
2) If multiple devices could not share the same transmit pair in 422 why would multiple devices be part of the standard.
3) that IS normally the case
4) everybody that find a 'cute' way to manhandle a standard rush to publish, those that follow the standard have nothing to falsely brag about.

Erik