omnifocus:///change-setting?ContextM...sParents=false seems like it ought to disable that, but I haven't had any success. I can get an acknowledgment that I'm changing the value, but behavior doesn't seem to change whether I set it to true or false. I'm also not 100% certain that it is expected to work in the flagged view, although I would agree that the default flagged view looks a lot like the Due perspective on the desktop (with grouping turned off) and that is a context mode view.
File those bug reports with Send Feedback... I don't recall seeing anything about these features in the release notes prior to it being shipped off to Apple for approval, so I didn't test any of it, and don't know if Curt or Dennis did either.