I would gladly sponsor the development of a reliable library that allows to programmatically produce compliant, accessible tagged PDFs with arbitrary layout[0], correctly printable and viewable by mainstream software.
(Considering it is a difficult, yet to be solved problem, I’d have to know the qualities of the approach that distinguish said library from not-quite-capable attempts that already exist before I commit my personal funds.)
I would not mind if said library’s developers release an entirely paid end-user GUI software based on it, as long as the library itself remains under active maintenance.
[0] Supporting commonly used paged media typesetting features such as headers, footers, page numbers, running headers.