Hi Sean, you can use WebIDs based only on path info. It's a feature introduced in PI Web API 2017 R2 (1.10). We've got some details on how to build them without needing to do the lookup call first. Check out this PI Square article...
Hi Ian, we've captured the bug separately in our product backlog, and it should be tied to a support case if one was opened. This feedback post is for the further enhancement.