Edit time window ran out:
WAG here would be that video out's also built into your SE Accelerator version. Optional adapter would have likely have been implemented as battery compartment door/connector and cable for that male edge card connector on your card as was the SCSI connector implemented in that manner on my 128K/512K expansion card. Such would not be needed for your SE card or a Plus version of same. IIRC it was for a TTL monitor, so the pin count would support that DE9 interface, but definitely not a daughtercard.
Don't recall what year I played with that, maybe they did implement drivers later on as implied in the ad? It was listed as "in development" at the time of my purchase. Comparison of PCB copyright/build/inspection dates of the variants pictured should yield some clues as would be driver comparisons.
@JT737 your card lacks the edge card connector for video output, so that's what makes this thread
very interesting.
@Sedorikku-taouno hopefully we'll see enough schematic development of your card to check that out. That's a higher capacity ROM than needed for accelerator function I think, so the video drivers are likely there on the 030 bus? Run Tattletech to see if it shows up as the equivalent of a DeclROM in the PDS/NuBus report?