+0 

Do you want to submit a PR for this?

Some thoughts:

* The current logic matches the logic before the warning was added.
* The proposed logic matches what the code will do after the
  deprecation period (it will only check for non-sequences).
* There is some value in the warning in that it lets you know an
  inefficient code path is being used (i.e. the conversion to a tuple).
* The proposed logic doesn't just change the warning, it changes
  what actually happens to the data.  IMO the change is for the
  better, but it is a behavior change and could potentially cause
  a failure in someone's code.
* The case of an object that is both a sequence and a set is
  likely very rare.