Optimization notification when < 15% freespace

My computer arrived with a small C drive partition so it stays close to full.  It appears Norton 360 v 20.4.0.40 disenables the wondows scheduled defrag in favor of disk optimization in Norton.  When I Norton ran disk optimization manually I found it will not run if <15% free space on the disk.  The result is that the C drive has not been defragged in years!  A notification from Norton 360 when optimization does not run would be helpful.  Optimization status in the monthly report would be nice.  A popup when it occurs would be better.  This may have been fixed in later versions.  I updated under my subscription today.  We shall see.