I think paging will be the way to go. That way you create say 50 rows from a template, which you can write in xml with checkbox and labels already in it. You can put any data you want in the row control, similar to how inventory rows have control.data={bagId=1, slotIndex=2, etc}. There were ingame scripts from Aug 2013 on XeNTaX forum, where loot window was paged, and it did pretty much exactly what I described - OnInitialize created a fixed number of rows from a template, and on EVENT_LOOT_UPDATED and when switching pages, updated data in those rows.
Later you can even make a search filter, e.g. events containing "TRADE" in their name
edit: can we even publish snippets from ingame scripts? It's so awkward to always tell people "there is something somewhere ..."