Is this box defunct now?

[Ronnie]

Will there be future updates for the T8, or is it just dead in the water now?

I have Amazon Prime and the T8 (for some reason) won't play Prime videos.

Thinking of upgrading to another box, but I feel it's a waste when I do have a working box, just no Prime.

 

[Nigelar]

I doubt there will be any firmware updates to the old t8.
As it runs android 4.4.2 there is no way it will run vanilla Kodi krypton 17.
However there are several Kodi forks out there such as Mygica, FTMC, CEMC which provide compatible functionality.
I use a t8 as our second machine and it runs well. Providing it continues to do that, no real need to update, in the short to medium term at least.
From your previous post you already understand the situation regarding Amazon prime on the t8.

 

[Bollocks77]

Just reading this Nigelar. I have a T8 Mini running real nice at the moment. Is this box also defunct of any future firmware updates?
Dave