[EpiData-list] editing qes- and chk-files?

Here is an old EpiData project with seven sheets (rec-files). The doc about the project describe how to add "user-defined variables". Sheet number 7 is prepared for this and the user just have to edit the qes- and maybe the chk-file with an text-editor.

It sounds realy old and obsulet. Am I right?

Convertet the rec-files to the new epx-format there is no need to edit the file manualy with hand, right? There is the EpiData Manager for this job, right?

Can I forget the qes- and chk-files if I have the new epx or are they related to each other?