You can master-out in the middle of a PhD program, which is frowned upon, but it is difficult to get funding if you directly apply for a masters degree.
Perhaps the solution is to decrease the negative cultural backlash against predisposed intention of leaving with a masters despite applying for a PhD, which is currently seen as some sort of betrayal of the adviser if you are going to have your grad students do boring work. It'll be a win-win deal in that case.