Web.Headers using MS Graph to handle (expected) HTTP-errors seems not possible. Any suggestions?

Me again with a clarification - @others please correct me/step-in anytime.

NOT all HTTP errors "halt" the query:

• 401 (and 403) will halt the query
• 405 (etc.) will NOT halt the query

Example of 405 NOT halting the query (I tested below on a local webserver that returned 405 on purpose):

let
    WebContentsWrapper = (url as text, responseFn as function) => 
    let
        response = Web.Contents(url),
        ret = try responseFn(response)
    in
        ret,
    wrappedResponse = WebContentsWrapper("http://127.0.0.1:5000/test", Json.Document),
    usageExample = if wrappedResponse[HasError] = true then "BOOM" else wrappedResponse[Value]
in
    usageExample

The above query did NOT halt, but returned as expected = BOOM:

And you CAN extract the error from the wrappedResponse record, if you want:

This could be a partial solution for handling NON 401&403 errors.

P.S.: If I would need to save my professional life by handling 401&403 errors in PowerBI 1) I'd implement a custom connector OR 2) I would use a simple "proxy server" hosted somewhere (internally or maybe pipedream.com etc.) that would always return 200 (so that the query doesn't halt) and a json record with actual HTTP error.

Specifically for MS Graph, I see there is also an integration https://pipedream.com/apps/microsoft-graph-api (haven't used it).

Please mark this as answer if it helped.