This works, but ONLY for the active message thread. If you delete the thread, it defaults back to the default message tone. This is ok for customization on the fly, but it is not a replacement for the original custome message tone, that is related to the individual contact, not the message thread.
I'd much rather have it the way it used to be, and not just limied to customizing the thread, which is an ok, but minor feature, that required additional steps to actively operate.
When is his update coming? Thread notifications and custom individual message tones are not the same thing. Samsung, this should be an easy fix, what is the delay?