spanNulls configuration no longer supported in Grafana Scenes Apps for State-timelines?

Hi I’m working on porting a Dashboard panel to a Grafana Scenes App.
When looking at the panel JSON to port it over to Grafana Scenes, there is this line:

...
  "fieldConfig": {
    "defaults": {
      "custom": {
        "lineWidth": 1,
        "fillOpacity": 100,
        "spanNulls": false
      }
...

Which I have replaced with a Panelbuilders.statetimeline() with a

        .setCustomFieldConfig('lineWidth', 1)
        .setCustomFieldConfig('fillOpacity', 100)
        .setCustomFieldConfig('spanNulls', false)

all of the above lines work, except for the last line, trying to set the spanNulls. Which results in the following error:

TS2345: Argument of type '"spanNulls"' is not assignable to parameter of type 'keyof FieldConfig'.

Has spanNulls keyword been removed or replaced with something else? A different keyword? Nothing?

If I switch the Panelbuilders line to PanelBuilders.timeseries(), the error disappears.

I have search online for hours, looking for a solution or hint to what the issue is and when the change occured, but I can find nothing. This page tells me that linegraphs support spanNulls, but nothing more.

Any insight to this issue would be appreciated.