As a user,
I want to be able to dynamically adjust the tempo of my project as an automation / modulation parameter
in order to
increase the freedom of creative choices when writing music at varying or nonlinear tempo.
This feature has been mentioned alongside different implementation specifics. Some people have been asking for automatable tempo (and alike), whilst others have explicitly asked for the ability to set a tempo per Pattern / Scene.
Both can be seen as valid approaches to yield the expected result. The exact way of implementation is not clear at this stage but both ways are reflected by this story as one of many possible solutions.