Why does the user need to wait to two confirmations? All services require one confirmation, and there is no difference between one or two confirmations. It would have been more convincing if 6 confirmations were requested.
But Unijoin mixer is not "all services" it's an independent mixer

If once can wait out for 4 or 6 hours to have their coins mixed, then waiting two block confirmations should be a problem.
My interest is in seeing how mixing USDT, a centralized stablecoin which can be frozen in an address, is going to work.