Set mirroring on a foundry with no fluid recipe

[sparr]

I am using create_entity to make a duplicate of another entity with some properties changed. One of the properties I would like to keep is mirroring. I'm stuck when the source entity is a foundry that has been mirrored but doesn't currently have a fluid recipe; I can't seem to find any way to make the duplicate foundry be mirrored, without temporarily giving it some random fluid recipe which I'd really like to avoid doing.

[Bilka]

From what I can test, /c game.player.surface.create_entity{name="foundry", mirror=true, force="player", position={0,0}} produces a mirrored foundry.