My ticket was updated the other day with a post saying they "asked our developers to make this manual adjustment for you once again". It appeared today. Was almost afraid to check the Spam Protection settings for fear it might disappear again. Since it came back with a 5.0 setting I set it to my 6.2 value and it's still there. Given the history of this it's like walking on eggshells every time I go back into Spam Protection wondering if Add Spam will disappear again.
Getting a lot if mileage out of that ticket!
I should mention that when I reopened that ticket to request it be put back again I included my arguments why preferences -> advanced -> reading -> extra headers -> X-Spam-score is not a substitute for Add Spam. Don't know if they bought that argument or not but at least I got the desired result...for now.