Smart Text Reflow + Data Merge
When using Data Merge, if text is too long to fit on the standard 2-page Master page spread, then InDesign should automatically create additional pages (either by repeating the Master spread, or allowing Master spreads to consist of more than 2 pages) utilizing Smart Text Reflow to continue the text thread instead of oversetting the text.
My personal use case: I am working with a teacher at a university to create a literature magazine, and need to compile multiple long-form submissions into one document. Since up to 200 students could be submitting work, it is important that this can be completed automatically, as manual entry for that many submissions would take ages! This could really help folks creating collaborative publications.
Have you tried using the Primary Text Frame to accomplish this? Using Primary Text Frame allows automatic creation of additional pages/deleting empty pages.
Adobe InDesign team