I get that you are trying to gather opinions of actual Sportsbook user here but you can easily get all the answers you would need with a simple search on your search engine and this is not in anyway trying to invalidate the opinions of others or yours.
It is not as simple, while there is a lot of information on the internet about almost anything that you can imagine, when it comes to technical questions it is unlikely you will find the exact answer you are looking for.And the question of the OP falls under that umbrella, only those which have created their own sportsbook or a similar service, or those which are developers will have the answer they are looking for.
But then, it would be worth noting that not everybody know how to use search engines, one who knows how to use search engines is likely to find answers to whatever he or she is looking for, answers to questions are lurking everywhere on the internet, like YouTube, Twitter, Facebook, medium, blogs etc, but then, our knowledge of how to use the proper keywords in our searches is what determines our success in finding the answers we seek.
That is why some people still need more accurate information about what they want. And they really need to find out a lot more.
I think the most important thing would be not accepting deposits (which isn't popular). If bets were made and settled on chain without having to deposit funds, just receive an address for the bet you want to make and send funds, that would be great. The only casino to ever offer this as far as I am aware was directbet.eu and they shut down after being scammed via double spends. I think requiring a certain number of confirmations would have likely saved the operation and kept it going. I'm a little surprised nobody has filled the hole that directbet left, but it's still wide open for the taking.
