It's about the Revit Connector, when importing back a ParameterUpdater object.

"//try to get element using UniqueId" is using the elementId again, but should this be the applicationId which would be used as uniqueId for Doc.GetElement()?
As far as I understood, it's also this Revit's uniqueId, which is saved as Speckle's applicationId when uploading.

https://github.com/specklesystems/speckle-sharp/blob/b67e46c0dc3eee8572f4cf9c9cdef339949f536b/Objects/Converters/ConverterRevit/ConverterRevitShared/PartialClasses/UpdateParameter.cs#L30C45-L30C54