Salvete omnes, I've encountered an issue with the Flare project import function (global project linking) and am recording it here for posterity.
We generally keep all of our docs in a few large projects, but as part of my translation workflow I create a separate Flare project that only has one the required doc in it (trust me, easier to import that into Lingo than the whole thing). Anyway, normally I create a new blank project, add an import file and get it to import the relevant .fltar and .fllng files with linked files included. Up until now that has always brought through the linked TOCs, topics, images, etc.
This time the document is a huge training slideshow, that includes a few "sub-TOCs" - i.e. smaller TOCs that are linked in the main TOC for the document. This time, when I tried to import the targets as normal, the sub-TOCs came through but the topics linked to them did not. Interestingly, even when I created an import file that explicitly imported one of those TOCs, the linked topics didn't come through.
The problem seems to be that files linked from TOCs are only included via the target, so if the TOC isn't linked by a target the files are not included. As a workaround, I'm going to create some dummy targets to link to those sub-TOCs, which immediately causes Flare to recognise that I actually do want those topics.