Ok,i found out that dual head images, although they seem to be written correctly on floppy disks (using the "head hack" i described earlier), and i was able to "CAT" them, there are in fact, loading problems, most probable because Amsdos routines can't manage tracks/sectors marked on Head=1, so, although i forced them (with the head select switch) to be written on the correct side of disk, they still have wrong head markings (head=0 instead of head=1).
So, finally, i manage to get rid of amsdos, and use custom fdc routines that can cope correctly with dual head images!And now, you can use the |DSK command to directly transfer to disk (no "select head" prompt needed any more...), practically any format with any heads/tracks/sectors (except copyprotected images)!
I've already use it to tranfer succesfully:
- orion prime 800kb image,
- R-type128 400k dual head disk image (this one is the only that you couldn't load using FDC emulation too

)
- 800kb parados 80tracks/dual head image
- 720kb pcw/+3dos and vortex images!
Of course,dual head images can be written only on a 3.5" disk drive, as 3" drives have only one head...

So,it seems that now, you will be able to use amstrad cpc to copy spectrum +3 and amstrad pcw images to floppy disks too!
For a typical 180kb cpc image ~55seconds is needed, where for larger images, time is proportinally longer, e.g. for ~400kb images 2x that time, for 800kb images 4x that time.
Also, unusual tracks (e.g. without 9 or 10 sectors/track and 512byte/sector) will need extra time too.