3Com also had a proprietary connector on the PCMCIA card edge, and an adapter cable of a few/several inches that went from that to a bulky RJ45 socket housing with an LED on it. It meant carrying the adapter with your laptop, but the experience during use felt a little better. The PCMCIA-side of the adapter stuck out a bit and wasn't a very solid attachment, but that might've been partly by design. If the cable gets jerked, the connector might pull out before dashing the much more expensive laptop to the floor.
Overall, I liked the Xircom RealPort PCMCIA/CardBus cards of the same era, which took up the space of 2 PCMCIA slots, and basically added 1 or more flush connectors to the side of your laptop. https://www.ebay.com/sch/i.html?_nkw=xircom%20realport
(I mentioned all 3 of these kinds of cards, in a vagabonding laptop writeup at the time: https://www.neilvandyke.org/linux-thinkpad-560e/ )
Ah thanks for finding the name, I tried to describe it in an older comment [1], on the same topic of Framework laptop expansions.
Agree with you, I hope such a version exists one day!
I do recall someone on the Framework subreddit saying that they carry a laptop around with them on a shop/factory floor, but mostly use wired ethernet when they stop and put it down on a workbench. Using a dongle wouldn't be great because it'd be something that would swing around unpredictably as he'd walk around a crowded room with lots of people and machines running. So in this case, this expansion card would probably be a useful step up from a dongle.
Regardless, a retractable "XJACK"[0] from the PCMCIA days might have been a better choice for this, if the hardware could be made "short" enough in that dimension. Downside there is of course fragility; I imagine they're easy to snap off.
[0] https://en.wikipedia.org/wiki/XJACK