The reason there are no add-on fills is that it is VERY easy to make your own. Look at "Create new symbol fill" page 375 of the AC 12 Reference Guide.
Also, I you have autocad and it has the patterns you are looking for, import an autocad file with the hatches placed and they will become ArchiCAD fills.
Erich
AC 19 6006 & AC 20
Mac OS 10.11.5
15" Retina MacBook Pro 2.6
27" iMac Retina 5K