If your commit message sucks,
I'm not going to accept your pull request. I've explained very politely
dozens of times that
my general guidelines
are absolute rules on my own repositories, so I may lack the energy to
explain it to you yet another time. And please, if I ask you to change
something, git commit --amend.
Beyond that, don't be shy about asking before patching. What takes you hours might take me minutes simply because I have both domain knowledge and a perverse knowledge of Vim script so vast that many would consider it a symptom of mental illness. On the flip side, some ideas I'll reject no matter how good the implementation is. "Send a patch" is an edge case answer in my book.