I've noticed, while analyzing the changes between ExtJS 6.5.0 and 6.5.1, that you introduced the use of scrollerEl and left scroller unnecessarily in the code of the Ext.view.DropZone.positionIndicator() method. This is not much, but will be taking a little amount of function time for naught. Well, I may be wrong, but I won't expect a getter method to have some side effects that enable the rest of the function to work. This may be a very small improvement but I hope you believe it is worth the report.

Here's the offending code: Ext.view.DropZone.positionIndicator().