Motivation
Currently TwoColConflict works for the wikitext namespace, but not in the page namespace because that apparently uses a non-wikitext content model, which would be needed for wikisource (see here: https://en.wikisource.org/wiki/Wikisource:Scriptorium/Archives/2017-05#Beta_Feature_Two_Column_Edit_Conflict_View).
Task
Find out, what would be needed to have TwoColConflict also work in the page namespace