Step It Up Blackjack

I saw this Blackjack side bet at the Downtown Grand in Vegas on my trip in May 2023. It is a side bet based off of the dealer's final point total. The table had a continuous shuffler and dealer hits soft 17. Note: Each bet covers both numbers, not a single number (i.e. betting on 17/18 wins if dealer ends up with 17 or 18).

Paytable:
17/18 pays 2 to 1
19/20 pays 2 to 1
21/22 pays 3 to 1
23/24 pays 6 to 1
25/26 pays 9 to 1

etgltd. c o m/step-it-up-blackjack (spaced because I am not allowed to post links yet)

Would somebody like to do an analysis of this side bet? I am not capable of doing it lol. At first glance, it looks like the 23-26 bust totals offer a lower house edge than the 17-20 totals, but I could be completely wrong. Thanks!

https://www.etgltd.com/step-it-up-blackjack

The above link, for convenience

I'll do the easy part. Here are some standard probabilities for the dealer,
Dealer H17, 8 decks

17 0.1333
18 0.1414
19 0.1355
20 0.1820
21 0.0748
BJ/21 0.0474
Bust 0.2855

so 17/18 has P = 0.2747; and pays 2:1; player's EV = -0.1759

19/20 has P =0.3175; pays 2:1; player's EV = -0.0475

Prob of dealer busting with 22, 23, 24, 25 and 26 can be approximately calculated with an infinite deck model. Straightforward, but I'm too busy to do it right now. I'm certain someone else will do this.
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Edit: OP says the game he saw was S17, so 8 deck S17 has the following dealer probabilities:

17 0.1452
18 0.1394
19 0.1335
20 0.18
21 0.0728
BJ/21 0.0474
Bust 0.2817

17/18 has EV = -0.1462
19/20 has EV = -0.0595