i decided to spreadsheet things this time so i am attaching the data here to view. here is the breakdown and it doesnt match what is stated...
first we need to break down the xp calculations in general. for this i used level 34->35 so:
12,818,888 - 11,478,888 = 1,340,000
value of the bonus is $110.55
to find the wagered amount based on 1.1% being returned, we just divide, so $110.55/0.011 = $10,050 should return that bonus
let us divide the wagered needed (10,050) by the xp needed (1,340,000) to get the value of usd per xp earned, which returns 0.0075 (so $0.0075 = 1 xp earned)
at the time of my bet, 1 btc was showing at the top of the site as $33,065.24
to earn 1k xp, we then take 1k * $0.0075 / $33,065.24 = 0.00113412 btc wagered to earn 5k xp
after making this bet, i went from 8,670,568 xp to 8,672,836, a gain of only 2,268
this results in less than 50% of what should be earned, meaning the rakeback is actually not 1.1%
bet used was id https://duckdice.io/share/bet/6e359622de9
i am seeing the same type of results with bch as well. based on what the spreadsheet is showing, it is a consistent return of 0.5% rakeback from the overall bet, not 1.1% and not 0.55%. please feel free to do the math as well. here is a google sheets link to make it easier since all the calculations are already filled in but you can create your own too :)
https://docs.google.com/spreadsheets/d/1WbupPzzt1RsSzdOPkZ6WOk8kU1FUWPwo8Fzj94up0eI/edit?usp=sharing