Family Historian User Group

I've been considering using the FH 7 Witnesses Window for entering shared events.
My question is: how well do these transfer by gedcom if i want to say export to RM or FTM to upload to Ancestry?

The "Give Witnesses Their Own Facts" plugin seems to be more for when importing from other software... Is it able to convert FH 7 created Witness or shared events to individual facts (which could be done on a copy of the project before exporting??) How do others that export to TNG or Ancestry handle this?

How Fact Witnesses export to other products depends on whether they support the custom 2 _SHAR tag or not.

The Export Gedcom File plugin knows what each product supports and produces an appropriate GEDCOM file.
Its Extra Options tab has the Witness Role 2 _SHA%u setting that defaults to the best alternative.
The products Family Tree Analyzer, GedSite, Heredis, Legacy, My Family Tree, RootsMagic, and TNG all support _SHAR.
However, TNG differs from the other products as discussed in TNG and FH event witnesses standoff (15833).

If the eventual destination is Ancestry then it would be better to choose the Move to Fact Note option that moves the relationships into standard GEDCOM Note text.

Your suggestion of using the Give Witnesses Their Own Facts plugin should also work but becomes more difficult to find all the people who share/witness the same fact.