Some of the Mi-24 characteristics referenced in the Smithsonian article (which I admitedly haven't read) are ones that I'd consider to be in the "urban legend" category:
"...Also I no longer consider the Hind a true helicopter after I read an Air&Space Smithsonian article about it that appeared a couple years ago.
Things about the Hind that stuck out to me.
Most of it's lift is generated by those two wings sticking out of the side, they aren't just weapons pylons. Also there is a 6 minute hover limit on the transmission before it has to be removed for overhaul.
The aircraft is more of a autogyro with a powered main rotor. It must maintain forward flight in order to keep from overstressing the mechanical components."
The wings do generate a significant amount of lift in higher speed flight, helping to offload the main rotor, but they're not at all necessary for the Mi-24 to fly. How would a wingless Mi-24 perform? Pretty much just like an Mi-17, which uses essentially identical engines, transmission, and rotor. The high incidence of the wings allows a higher top speed and the incidence and anhedral serve to minimize the wings' negative impact on hover performance.
I can't say anything definitive about a 6-minute hover limit, but I've seen Mi-24s and Mi-17's hover for fairly long periods, such as during an SAR demo.
Just my opinions, based on observation.
"That's so stupid! If they're so secret, why are they out where everyone can see them?" - my kid