When the first page uses a master page different from the normal left and right, Mif2Go identifies the master page, creates the required header and footer (if used), and picks up any first-page graphics and untagged text frames.
When Mif2Go encounters a page (after the first) that does not use the default left and right master pages, Mif2Go starts a new output section with that page, and sets a new first-page header and footer according to the FrameMaker master page used.
Word uses section breaks to permit the kind of format changes FrameMaker handles with a new master page, such as a change of header/footer. If you like what you get when KeepSectBreaks=Yes, use this setting; if not, set KeepSectBreaks=No.
> 5 Converting to print RTF > 5.4 Specifying document layout options for print RTF > 5.4.9 Converting headers and footers > 184.108.40.206 Converting headers and footers on different master pages