That's what read reciepts are except your incorrect. In simplex the 2 checks is not for read if you read the docs you will see it indicates the message was received that the smp was able to successfully send it to the other. However that does not mean they read your message.
This was discussed as well because in other apps 2 does mean the message was read but not to evgeny it don't & that's what mattered because hes the facr & leading developer who made it.