Rated 5 out of 5 stars

A life saving plugin for intranet crm's.

However I could not get any documentation, this is what I came up with by analysing the source and trial and error:
jsPrintSetup.setOption(optname, value) is what you need.
optnames:
'orientation', 'marginTop', 'marginLeft', 'marginRight', 'marginBottom', 'footerStrCenter', 'footerStrLeft', 'footerStrRight', 'headerStrCenter', 'headerStrLeft', 'headerStrRight'. These should be self-explanatory, after setting these, you must save:
jsPrintSetup.setOption('orientation',0);
jsPrintSetup.setOption('marginTop',2.54);
jsPrintSetup.saveOptions(jsPrintSetup.kSaveAll);

btw, orientation is 0 for portrait, 1 for landscape

This review is for a previous version of the add-on (0.7).