Just another point to consider: sometimes reviewing a PR and getting it up to your standards is significantly more work than doing it yourself.
If you don't have time to implement it, there is a chance you don't have time to review it.
If it is like that, you can simply say you don't have the bandwidth to review, and/or you don't want the feature in your repo. You can emphasize that they can always simply fork the project and do whatever they want with it.
If you don't have time to implement it, there is a chance you don't have time to review it.
If it is like that, you can simply say you don't have the bandwidth to review, and/or you don't want the feature in your repo. You can emphasize that they can always simply fork the project and do whatever they want with it.