I guess I have found a inconsistency in the Twitch EventSub documentation, the documented sort order of event attributes for the Channel Points Custom Reward Redemption Add Event doesn’t seem to be the way they are are returned by the EventSub (see screenshot).
I hoped to find some place at github where I could simply add a PR. But since I couldn’t find one, I reported it via the “Provide feedback for this page” button at the end of the documentation page (where I forgot to mention the main id as well).
In fear that might be a dead and I am simply reposting this issue here. If that was a good place, this issue can be archived.