yeah passing a tensor that are computation result of some random variable is fine, as they are also represented as a tensor, but you need to account for jacobian when you do inference as transformation of a Random Variable is more than just the mapping of the value.
Here is a quick example: All-that-likelihood-with-PyMC3/Regression with a twist.ipynb at master · junpenglao/All-that-likelihood-with-PyMC3 · GitHub