[Quoth]

I installed KOReader and Menu "one click" on the Elipsa purely for PDFs. It has auto and manual settings to crop margin and ability to change "contrast/brightness" for poor scanned PDFs to have black text and white "paper". No special jailbreaking. Just down load the files (different scripts for Mac, Windows, Linux), connect via USB and run script. Files & instructions on this site.

I've no idea personally about ADE/DRM, but it has the menu option to register and people here use it. Also it may be that DRM files only work on the built in PDF viewer which can't crop. The Zoom to lose margins is useless except for a 3 or 4 page datasheet or a short manual.

I use the Elipsa to read PDF books (they are not real ebooks but electronic preview for paper) from public domain, manuals, old scanned magazines (PD) and our own PDFs that are uploaded for POD paper. Easier than checking on Laptop even though it has a 24" external 2K screen.