Yes. I bought a Futura IISX for my IIci back around 1994 or 1995 after SuperMac bought E-Machines (but before Radius bought SuperMac) and SuperMac was clearing out the old E-Machines stock.
Much later, after Radius and Radius Vintage were dead and gone, an Ebay seller appeared who seems to have ended up with Radius Vintage's stock. The seller ID is Macmetex. I bought a couple of the Ethernet daughter cards from him and a second Futura IISX several years ago.
As far as I know he is out of the RJ-45 daughterboard, but he might have some of the coax ethernet daughter boards left. He's still around as I bought a new front panel for my Radius 81/110 from him recently.
I'd have to look to be sure, but I'm pretty certain they were different. For one thing, Radius had not yet purchased SuperMac/E-Machines when the Radius Thunder IV GX series came out (I think). I could be wrong though. Hmmm. Didn't Radius get some of the technology for the Thunder IV GX from SuperMac? Also, IIRC the Futura card has one connector near the bottom fo the card for the DSP, while the Radius has top and bottom connectors. I also have a very vague memory that the Futura II DSP card had two DSPs on board, where the Radius card had four.