The time duration streaming intervals are functioning as expected in ArcGIS Field Maps 21.3 and 21.4. The new vertices do not drop for a streamed feature (using time) if accuracy or distance requirements are not met with respect to the previous vertex. The distance traveled from the previous vertex must be greater than the current GPS accuracy divided by two. For this reason, using small time intervals for streaming may not be useful unless using a high accuracy GPS device or moving at faster speeds.