I worked in a lab where we invented basically the same scheme in about the same time. I still have a box full of those little grey plastic RJ-45 to DB-9/15/25 M

I worked in a lab where we invented basically the same scheme in about the same time. I still have a box full of those little grey plastic RJ-45 to DB-9/15/25 M and F adapters. The cable plant improvement was good - we could punch down CAT-3 (later CAT-5) into keystone jacks and patch panels without regard for whether it was RS-232 or RS-422/485. The big advantage is that you only have one type of wiring and that it's flexible as to whether it was 10Base-T (later 100) or serial. I used a different pinout that worked well for us: 1. almost all of our systems were 3-wire (no hardware handshake, just RX/TX/GND). In a few cases we needed extra signals and then used the other two pairs. 2. we treated each RS-232 as a pair of GND/signal. Put Rx/GND on 1/2. Tx/GND on 3/6. this provided a little better "shielding" because the ground wire was twisted around the signal wire vs. having TX/RX twisted with each other. 2a. In RS-422/485, used the same pairs but RX+/RX- on 1/2 and TX+/TX- on 3/6 with a chassis ground on one other pin. 3. By using 1/2 and 3/6 it made standard Ethernet cables "straight-through" and made Ethernet cross-over cables into null modems. I wired terminal servers and workstation adapters "backward" (not unlike Ethernet switches vs. hosts or DCE/DTE). This made for very few crossovers required. This kept our wiring neat and very flexible. You can color code Ethernet vs. serial. The biggest disadvantage was the shitty stamped tin pins in the cheap adapters.