This suggestion is similar but different to the option to create circles here: https://community.esri.com/t5/arcgis-web-editor-ideas/capability-to-draw-circle/idc-p/1498389
Using Pro, the Buffer editing tool allows a user to create a buffered version of an existing feature. This functionality appears to be missing from both the generic AGOL map editing tools and Web Editor.
My current issue is the inability to re-use a "sketch" in the Notification instant app for selecting addresses from, which is frustrating for users and compromises consistency. The Notification app does allow the buffering functionality in the selection tools that would be useful here: allow the user to use any kind of geometry to create a shape, and the selection can be set to buffer that shape. But because that drawn selection can only be use to create a single list, I was hoping to create the selection area as a feature in a special layer as a workaround. (I'm aware of the Create Buffers geoprocessing tool, but I think the extra steps required would discourage our users from using it).
This one-step functionality that the Notification selection creation would be useful in many places, including Pro. But even the Pro editing tool functionality would address my issue.