Please increase $wgMaxArticleSize to 4 Mb in LocalSettings.php for ru.wikisource. Because books are often larger than the 2MB limit. (Let me remind you that the UTF-8 encoding for Cyrillic reduces the size of texts by 2 times, also various included templates are used.)
Reason:
Splitting of a literary work into many site pages is not convenient and labor-intensive for editors. Laying out one work into separate pages takes up almost all the free time that user can be allocated to Wikisource during the day. This time could have been better spent.
In practice, reading split pages is inconvenient for readers in many cases. Especially acute problem with reading on e-books. Exporting these parts to files is too laborious and bugged (it is easier to consider it not working, this deserves a separate discussion). It is easier for the reader to go to another site where to download the entire page with the work or a file.
It is also impossible for the bot to import many texts into Wikisource from sources larger than 2 MB, bc wikiAPI blocks importing.
[[ https://ru.wikisource.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D1%82%D0%B5%D0%BA%D0%B0:%D0%90%D0%B4%D0%BC%D0%B8%D0%BD%D0%B8%D1%81%D1%82%D1%80%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5#%D0%A3%D0%B2%D0%B5%D0%BB%D0%B8%D1%87%D0%B5%D0%BD%D0%B8%D0%B5_%D0%BC%D0%B0%D0%BA%D1%81%D0%B8%D0%BC%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B3%D0%BE_%D0%BE%D0%B1%D1%8A%D1%91%D0%BC%D0%B0_%D1%81%D1%82%D0%B0%D1%82%D0%B5%D0%B9 | By request]] on the admin forum ru.Wikisource.
Difficulties:
I see difficulty only with the syntax highlighting gadget in the browser editor, which is auto-disabled on large pages.