We use FME Desktop and FME Server to manage important processes that read from and write to ArcGIS Online (and to a lesser degree Portal for ArcGIS / ArcGIS Enterprise). The interface to specify an item for ArcGIS Online readers and writers has improved dramatically in recent versions.
A major limitation is that items are specified using a group name and the item name. It appears that more recently the item ID is also incorporated, which will help to resolve conflicts if items and/or groups have the same name. It seems that folders within an owners content may also be used in lieu of groups, which is convenient, but when used to specify an item, only adds to the issue described below.
We propose that ArcGIS Online items should only be specified by their ID in readers and writers. The ID is unique and constant, and is how Esri references and manages content within their systems. It's also how other third-party vendors often reference items. We'd still like to be able to search by item name, but as a large organization, there are various circumstances where item names need to change. These changes currently cause process breakage in FME and require significant re-work.
Please consider this for future releases of FME. We're happy to provide additional information, if helpful. If it is currently possible to specify items solely by their ID, we're interested in that.
