The practical logistics are almost certainly more daunting in reality than in theory.
While one might anticipate some elevated scrutiny and perhaps overtly uncooperative attitude from Canadian border officials, at least occasionally, if and when, as is likely, you are perceived to be, in effect, gaming-the-system (which of course is what this would amount to), actually my best guess is that the American border officials are the ones more likely to make this less convenient than hoped. How frequently and to what effect, whether it is enough so as to practically preclude it working, that's really guessing. Individual personality may have some influence.
A day partially in Canada, no matter how partial, counts. So that part of the equation works. But sooner or later the practical logistics factor in the equation will dictate how it goes.
In the meantime, take note that some anecdotal reports are more reliable than others, meaning some are, well, not particularly reliable. Caveat emptor or something akin to that.