I think users can share baseline API code to decrease the workload.
See some earlier API discussion in this forumpost:
I have once tested such XML extraction and I posted in the above forumpost which fields need attention in Manager for this to work smoother and that is besides getting the finalized API. So after ploughing through this conversion to XML I can only say that this process is loaded with technical and localized complications. A basically standard multiline invoice is between 200-300 lines of XML code. Therefore it is my opinion it doesnt matter how far Manager can go in setting up XML code, theme, template, custom report or report transformations for this purpose, I think there will always be need for local pruning in some other software. So why not just move all the “raw” data from Manager to this other software with finalized API where the XML code is structured 100%. Such pruning can be done for each government or tax authority’s liking in corresponding countries, states or whatever it may be. Maintainance of code, going forward, can also be done through the API as it has the flexibility and speed locally for XML coding purposes. So although not being a programmer, API is my bet 