So far I'm not seeing any concrete evidence that the general idea of polyphasic sleep is anything but wishful thinking. I recognize that anecdotes are not data, but after a while the complete lack of even anecdotes of success, after the number of people trying it publicly, is itself evidence of a sort.
"Biphasic", or "afternoon naps", by comparison, are indeed quite natural, though I'm not sure I've seen that much convincing evidence that night sleep+naps is universally better or worse than just night sleep. Individual differences are probably swamping any attempt to make sweeping declarations. Personally I do a lot of "just listen to my body" here and over the years and various growth and health stages I've swung all around on what I seem to need.
Polyphasic sleep for a month means exactly nothing. I've been sleep deprived for periods longer than that, sleeping less than six hours a day. Doesn't mean that "sleep deprivation works", or that it is healthy, or that it can be sustained.
Not to say that polyphasic is healthy or anything, but despite the slightly weird feeling, I feel much more functional when polyphasic than when sleep deprived.
Maybe a mixed solution would work, biphasic sleep during the week when you're maximising productivity, monophasic when it's less important (holidays etc) to get around the constraints. Not sure, I might experiment with it.