Is current RateLimit header (to avoid throttling) implementation still a beta implementation of IETF draft-03?

What type of issue is this?

Question

What SharePoint development model, framework, SDK or API is this about?

SharePoint REST API

Target SharePoint environment

SharePoint Online

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

SharePoint API documentation / implementation about avoid being throttled.

Issue description

In the article Avoid getting throttled or blocked in SharePoint Online there is this note:

These headers are currently in beta and subject to change. At the time when the headers were adopted, the IETF specification was in draft. The current implementation is based on the draft-03 of the IETF specification. There is the potential for changes when the specification is final, and we will adapt to those changes in the future.

As with the many support calls we had with Microsoft they refer to this article and suggest we implement this handling of RateLimit headers on the client side. This note is there for years, but in the meantime the IETF spec is already busy with creating draft-08.

Questions:

1. Is the RateLimit headers implementation still in beta? and when is it expected to be production ready?
2. What are the plans/schedule/roadmap to implement a newer versions of the IETF draft? The newer versions may supply better partitioning of quota.
3. Are there undocumented throttling tactics? I heard a support engineer mentioning we are victim of a 'sequal throttle', but this is not documented in the article .