What I would do is to buy a 24" widescreen full-hd monitor for the librarians needing this functionality and instruct them to use two staff_client windows. Under extreme pressure buy two monitors and a GPU. This way you get a minimum of 4 records visible. Monitors are so cheap nowadays (its crazy), where programming work is not.
You can edit marc records in a text mode, so copying and pasting large chunks is a breeze. OAK
