The last firmware available for the Metabones EOS -> FE Smart adapter v. IV is 0.45 (I just updated the one I have just bought and which came with version 0.44. The explanations said that version fixes a problem where the body was seriously overexposing some shots. That bug was introduced by the previous update (0.44).
You can check the Metabones firmware version the same way you check for the body firmware version : it is in the same panel (5 or 6 in the rightmost tab of the menu, the one with the wallet icon). You need to mount both the adapter and a lens to view it.
I really had the overexposure problem with the 0.44 firmware and the TSE lenses.
Now which firmware you need for the Tamron ? I don't know.
With my older but sharp, light and compact 28-75mm F2.8 zoom in Canon mount the AF isn't supported neither with the smart adapter III, nor with the IV. The Tamron 90mm F2.8 macro (an older version without IS) was able to AF very slowly on the A7r and Metabones III. But don't AF anymore with the A7r2 and Metabones IV (that was with firmware 0.44)