I hope this helps you . You can add and event listener iron-overlay-opened in paper-dialog which will fire after the paper-dialog is opened. In that listener you can simply put your code to reset the scroll position of the paper-dialog-scrollable. Example Code:
should help you out You could use selectors like ::shadow and /deep/ but they are deprecated. If an element doesn't provide the hooks (CSS variables and mixins) then you're basically out of luck and there is non such hook for .scrollable. What you can do, is to create a feature request in the elements GitHub repo to support additional selectors by mixins.
hop of those help? As suggested in the link you provided, give the paper-dialog-scrollable some id (e.g pds) and then add the following code: this.$.pds.$.scrollable.scrollTop = this.$.pds.$.scrollable.scrollHeight;