I have played at all mainstreet casinos and also oneclub casino. I can tell you that when you make a withdrawl from mainstreet, it leaves the account immediately. You can’t reverse either. At oneclub, the withdrawl sits there for weeks and you can reverse it. This behavior reminded me of the casinos like Prism, Coolcat etc.
Even though they look the same and use the same processors, they are definitely not the same standard.