If the option is "off", then LibreOffice converts a SmartArt to a metafile in case of Writer, and tries to convert but currently fails in Calc, and do not convert in Impress.
I see no advantage for a metafile and request to set the default for the option "Convert SmartArt to LO shapes or reverse" to "on". Then all modules would behave the same as default.
More details and start of discussion is in https://lists.freedesktop.org/archives/libreoffice/2022-October/089498.html
The commit message of 2eba5391d3fa3232ba2b0a187c4c51736ab2ec3d says "The point of this menu option is that locked Smart-Art shapes would preserve the original XML files attached so they could be exported back to docx with no loss."
If we switch the conversion on, wouldn't this potentially break the round trip?
This does not affect the export result if the user doesn't change the shape. What this would change is that currently the group shape is converted to a metafile to make it ~impossible to change it, while the new way would be to present it as a normal group shape, so you can edit it.
Given that this is a generated shape, you have the trade-off of not being able to edit (but then export of the smartart markup + generated shapes is easy) vs not having smartart markup for the edited version of the generated shapes.
Given that the proposed new default seems to work reasonably in Impress already, I don't see a problem.
So let's do it. Low priority since we aim to implement a fully SmartArt compatible solution.