As a first step, we should make sure that the call to /orderableFulfills is unnecessary on the physical inventory screen. It seems that all of the necessary information should be contained in the response of the stock card summaries v2 endpoint. If that's indeed the case, we should get rid of that call, make any necessary changes in the code, and submit a pull request to the core with this fix. If there's anything that prevents us from removing this call, we should post the reason as a comment in this ticket and then move it to done.
Call to /orderableFulfills is either removed from the physical inventories screen or the reason for this endpoint being required is posted in this ticket