Both Marvin 2.x and Marvin 3.x running under iOS 10.1.1 have a serious bug. Both ignore page-break. The CSS shown below works except for the page-break. The page-break is ignored. This should be fixed ASAP.
Code:
.chapterOpenerText {
page-break-before: always; <--- GETS IGNORE in 2.x and 3.x
padding-top: 1em;
text-indent: 0;
}