Exporting (FAL) files works. i fiddled with ext:introduction recently and had to do this various times now in v8 and v9:
It depends on correct export configuration:
Usually, you do not want to select the sys_file* tables in "Include tables:", but instead select them in "Include relations to tables:", and DO NOT select them in "Use static relations for tables:". With this configuration, files related to for instance tt_content elements are exported, but only those, and not other files which are not connected to your main "Include tables".
Note: ext:introduction now comes with a well configured export preset injust import that row into DB and play around with the preset a bit.