On the off chance anyone seeing this is interested, I have a solution uploaded as part of a module I wrote for screenplay and stageplay writing: https://github.com/cjayross/drama.mkiv/blob/4a9b2576c8630fd03352d95f99456092... The solution ended up being very detailed and tightly coupled to this particular problem. However, the general approach was to use box registers to capture the portions of dialog marked using a command sequence (`\continue` in this case) that designates acceptable locations to insert a page break in the dialog. The markup is then placed into the document in pieces with each placement testing the `\pagetotal` against the `\pagegoal` to measure whether the current piece will fit on the current page. This solution had to up using `\synchronizeoutput` as opposed to `\triggerpagebuilder`. I'm not sure why there's a difference in behavior between the two, but the former seems to fix bugs where the `\pagetotal`s would output the measure of the previous page rather than the current one -- leading to sporadic page breaks.