Hi Leah,
Query 1: Unselect or set null on SelectedItem on SfPicker
We have validated your query and currently, we don't have support for “Setting the null for SfPicker”. Already we have logged a feature request on this, and it can be tracked through our feedback portal below.
Feedback Link: https://www.syncfusion.com/feedback/2306/provide-the-nullable-selecteditem-for-sfpicker
Please upvote this feature to make this our priority. While this feature itself is important we will prioritize the features every release, based on the user demands.
If you have any more specifications/suggestions for the feature request, you can add them as a comment in the portal.
Query 2: How to remove or shrink this gap?
In the SfPicker the first item is shown in the center of the view. If we scroll, the selection will change based on the center position. Based on the Picker implementation the space will show and we can't remove the gap.
Regards,
Ruba Shanmugam