I found a very simple trick to work around the microbanding in the top and bottom on my 1500W.
I cut a spare sheet in two and I tape those pieces using a very delicate masking tape to the top and bottom of the sheet I want to print on.
Basically from an A4 = 210 * 297 I get a "double A4" 210 * (297/2 + 297 + 297/2). I then set up a custom format in QTR and tell it to print in the middle. It works perfectly.
I guess this custom format could be added to the list by editing the printer PPD file by I haven't tried yet.
Regards,
Federico