I just used this plugin again after not needing it for ages, but had problems.
The export to text was limiting to 50 posts.
My first attempt to export everything failed, and timed out, so I did it in bits. My first two exports each had 51 lines, 1 header and 50 posts. I thought that was just a co-incedence, until the next and the next, each had the same 1 header + 50 posts.
I assume that any posts over 50 have been dropped. I ended up with 200 posts in total, but was expecting more like 2,000+.