New Deal or No Deal Roulette game - HE calc

I came across a new Deal or No Deal roulette game at a local casino that is different from the game Woo analyzed a few years ago.

The game is a roulette game with the numbers "1-36", "0" and a "B". So basically 38 numbers. Like American roulette but instead of a double zero you have a "B"

When you bet on "B" and the ball lands on "B" you trigger the bonus game which is a game of Deal Or No Deal.
You have to bet on the B to trigger it

The roulette payouts are like any other roulette game so my first thoughts are that the game has a 5,26% house edge but when checking the rules on the screen I saw on the bottom "RTP 97,30%"
This seems wrong to me so probably the B bet has a lower house edge.

The deal or no deal game has 26 boxes: 1, 2, 3, 5, 7, 10, 12, 15, 17, 20, 22, 25, 30, 32, 35, 37, 40, 42, 45, 47, 50, 60, 70, 80, 100 and 200.
This is a total of 1007 and an average of 38,73.

EDIT: The banker offers are lower than the average but not always, sometimes they are.

Am I right in thinking the "B" is (by approximation) a no house edge bet?

Any more mathematically inclined person could confirm this?

Off the top it looks like you would come into this game with the idea to just bet on "B" and you would probably need a bank-roll of $6000+ for every $1 you wanted to bet, if the game and bonus is EVENLY WEIGHTED.

To see if it was evenly weighted, you would have to look at about 494,000 spins, which should have about 13,000 hits on "B" and about 500 in each "box" in the "deal or no deal" bonus.

Working out the number of spins to count is not my area of expertise so the above may be wrong and/or you could ask the casino what the chance is for:
1. hitting "B"
2. hitting (a) 1 (b) 40 and (c) 200 in the bonus game.

The reason I wouldn't ask for the chances for all the 26 boxes is because it may tip them off to "something being wrong with the game", from the Casinos point of view.
There may be a pamphlet or information sheet you could ask for that has the information you are looking for as well, it may be safer to ask for this first.

You may be correct that the "B" bet has roughly "no house edge", but you would need more info, by doing at least one of the things I mentioned above.'

There may be people commenting that the "casino wouldn't have the game if it could lose" and most of the time they would be right, but I have also seen plenty of games in the past that are straight-up in the players favor, so it is at least worth further study.

This is all i can think of based on the information provided in the OP, so hope it was helpful.

Edit:
Is the RTP of 97.30% listed for the game the average " if everyone had $1 on each number" RTP, or is it the best RTP for the game ?
If the answer is that it is the best RTP then the boxes are not equally weighted in the "deal or no deal" bonus game, for example the smallest 13 boxes may roughly have a combined 53% chance and the largest 13 boxes may roughly have a combined 47% chance of happening.

I told one of the employee that their listed RTP was wrong, that if I bet on 11 black I will only get 36/38 or 94,74% return and that their listed rtp is wrong. He went on to get someone from the "technical staff" and he told me that if you bet on "B" you can win up to 200x your bet and that the listed return is the average of the game itself.
I found that odd and, like you said, didn't want to ask further questions to that guy so I don't make him suspicious.

So if "B" is evenly weighted (I think it is) and the bonus game is evenly weighted (no idea about this) and I never take a banker deal, this would give a player edge of 38,73/38 = 1,92% edge ?

1.92% sounds right to me, just need to find out what the minimum number of games you need to play to have a decent test of this game.

Since the rigged HiLo games on a major UK game brand (even odds weren't true even odds) a few years ago I'm very suspicious.

Playing a great number of games isn't really doable. 500000 spins would take 5000h.