This seems to be one of those many instances where I would trust more results obtained using one of the principles of experimental economics: When asking participants to do things that require effort, provide a reward that correlates positively with their performance on the task.
In addition, let's say there some validity to the result that two spaces provides a slight benefit to a subpopulation of readers. Does it matter? Is what is true for the general population true for your readers? What is the cost to YOU, the author? Maybe through self-selection, most of your readers are those who are comfortable with single spaces.
I typed a lot of papers a mechanical typewriter. Then I started using WordStar. In either case, I learned myself and it never occurred to me to leave two spaces after a period. No one around me complained. Nor did I ever see anyone use two spaces after a sentence. And, I was around typewriters a lot with a journalist father and a secretary mother.
I did not learn about this rule until I came to the U.S. for grad school to witness the horror of people hitting the space bar twice after each period on WordPerfect.
Apparently, being completely oblivious to the alternative was not much of a hindrance.
