I'm reading messages in TB but am now getting extra verbiage such as notifications about what TB is doing while NVDA is automatically reading the new message.

Reads something like this:

I bolded the extra verbage.

Moved 9 messages from NVDA to Trash
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Re: [nvda] Why isn’t there a browse mode for windows desktop apps?
Hi,
  Apart from recent apps, traditional desktop apps are not really web documents nor exposes elements   in a way that is suitable for browse mode navigation.
bobcat11@...: Moving message to Trash…
Therefore there is no need for a dedicated   browse mode functionality....