Multi-page text annotation

I am trying to annotate multiple pages of text data for a QA task where I highlight the span of text where the answer was found. You can do this in a clunky way using the QA template with multiple text boxes, but this doesn't scale well when you have 50+ pages of text with metadata for each page. Each page is free-text, not a PDF so the multi-page PDF template doesn't work either. Is there some way to highlight spans across many pages of text, each with their own metadata? Ideally I'd like the user to be able to filter by the metadata for each page as well. Thanks.