auto-save (draft) pull requests

I have been very frustrated lately with the workflow for pull requests.
As your UI suggests, you must first enter a title.
Then, you can add more elaborate information for the reviewer.
The way I do that second step is that I look at the diff. So, I click on the diff instead of the commits.
Then, I realize I (BTW, ALWAYS) want to ignore white spaces. So, I click on the ellipsis, select ignore whitespaces and BAM! all my work on this pull request is lost because the page refreshes.

Either find a way to not lose my work when selecting ignore whitespaces or please auto-save my draft (like you do in many other parts of the Atlassian ecosystem).