Well it definitely DOES work. I am not sure how you get Archimedes
images onto it - or even if you can without modified software (seems to think they are Amiga images which do not seem to be compatible) but I can get it working in the way I wanted - simply as a blank floppy image I can read/write to.
The jumper needs to be in the upper right corner connecting the centre right pin with the upper right pin (A3000 can only EVER have ONE floppy drive

)
Next I created a RAW image: Track type MFM, 80 tracks, 5 sectors per track, 1024 sector size, 0 sector ID start, 300 RPM, 250000 bitrate, 50 GAP3, 1 interleave, 0 skew.
When I booted, it accepted it but it didn't work (directory error). Maybe one or more of those settings could be better?
Anyway, when using the Archimedes to format that image, it works perfectly and verifies too. Now I can read/write files to it with no problem. So it does do everything I wanted it to.
I hope this is helpful for other Archimedes users (maybe even 8-bit BBC users too?)
I might look at getting the Archimedes ADF's to work and write any necessary software to do the conversion that will probably be necessary if/when I get the time.
Again, if I do I will post it here.