I don't understand why I can not choose a font in DOM when I export the subtitle XML as non SMPTE from AnnotationEdit.
If you don't tick the "Load Font" checkbox in SubtitleEdit you get a subtitle XML file with no <LoadFont> node, so DoM assumes there are no configurable fonts in the file. Maybe this should be improved. If you tick "Load Font" you should get the choice of font in DCP-o-matic.
Also from what I understand for a SMPTE DCP a subtitle font selection seems to be mandatory. But when I don't set a font in DOM and I don't get an error message while checking it, does this mean that DOM sets a font automatically for SMPTE DCP subtitles ?