Tamron manual VC instructions below.
Note in particular:
1. Turn the VC switch OFF when using tripod.
2. The VC mechanism may introduce errors during long exposures.
3. When the shutter button is pressed down halfway, it takes about 1 second for the VC to provide a stable image.
4. When VC is not used, set the switch off.
How to use VC mechanism
1) Set ...
Do keep in mind that there would still be a big factor limiting the use of eg an f1.2 stabilized prime: If you are in the shutter speed range where camera shake becomes a potential problem... subject motion also does. People, foliage, vehicles... move. Neither OSS nor tripods help with it. One reason to use ultrafast primes wide open in low light situations -...
The Tamron SP 45mm F/1.8 Di VC USD is the exception to the rule:
I own it and use it on the EOS 6D, it is a very fine lens with image stabilization and weather proofing too.