Changes should first be discussed by opening an issue, not by creating a pull request. This gives an opportunity to discuss whether the change is likely to be merged, and the best way to go about making the change.
Pull requests created without an agreed approach in an issue are unlikely to be merged.
Unfortunately, I currently have relatively little time to work on open source projects. As such, my preference is often to implement changes myself: this is usually less time-intensive than reviewing changes and getting them ready to be merged, and tends to make long-term maintenance of the code easier.