Additionally, do paths have to be tagged in tables for them to display properly as reflowed text? If so, they will fail PDFUA for having paths tagged in <TD>. I have reflowed a table when just table text had been tagged and it was all jumbled up/didn't display properly.
Why is reading order not based on tag structure? It seems like the most reasonable thing to do. Basing it on content order just adds an additional layer of work.