Exporting item type "film" merges scriptwriter with other contributors

Debug log ID

J4GNPRJ5-refs-euc/6.7.163-7

What happened?

If you use Zotero's Connector browser extension to create an entry for a movie from an IMDb page, it creates a Director field, a Screenwriter field, and then several Contributor fields for actors. However, on export the Screenwriter and Contributor fields are merged together:

@video{Loach:DanielBlake2017,
  type = {Drama},
  entrysubtype = {film},
  title = {I, {{Daniel Blake}}},
  editor = {Loach, Ken},
  editortype = {director},
  editora = {Laverty, Paul and Johns, Dave and Squires, Hayley and Percy, Sharon},
  editoratype = {scriptwriter},
  date = {2017-06-09},
  publisher = {Sixteen Films, Why Not Productions, Wild Bunch},
  abstract = {After surviving a heart-attack, a 59-year-old carpenter must fight bureaucratic forces to receive Employment and Support Allowance.},
  keywords = {bureaucracy,psychological violence,United Kingdom},
  annotation = {IMDb ID: tt5168192 event-location: United Kingdom, France, Belgium}
}

In the above case Paul Laverty is the screenwriter and Dave Johns, Hayley Squires, and Sharon Percy are actors.

Now I don't have the foggiest idea how a BibLaTeX entry for a movie should look like, this is the first time I have ever needed to create one! I have also read the entirety of #1837 and have acquired some understanding of how this is an area where there seems to be little clarity.

However, given that Zotero does distinguish between a scriptwriter and other contributors, it does strike me that they probably shouldn't all be merged into one field on export. Frankly I don't really care what happens to the contributor fields as I suspect no bibliography style would ever include them.

Thank you for this absolutely invaluable extension!