These Xiaomi air purifiers are absolutely top, they filter out everything you shouldn't breathe in, including pollen of course. The built-in one can also filter formaldehyde, with the Xiaomi Air Purifier 4 you get one device and one filter, you don't have to worry at all, 99.97 % is filtered with a genuine HEPA 13 filter (in my opinion, there is no reason to spend 3 or 4 or 5 times as much for alternative devices).
The Lite is only minimally cheaper, the surcharge is not that great compared to the normal 4, I would take the Lite after all.
By the way, the filters last much longer than stated by the manufacturers, because these filter change intervals suggested by the devices are certainly important for regions with very high air pollution, in our case they last for years.
Here is the manufacturer's website (Global) with a lot of additional information about the device:
https://www.mi.com/global...I have it in my office and I don't have a problem with pollen, so it seems to work. However, with my Dyson Purifier Humidify + Cool Formaldehyde in the living room and bedroom respectively, the air quality indicator seems to be better.
But read the top comment on the lite, the filters are the same as far as I know:
Xiaomi Mi Smart Air Purifier 4 Lite (43 m²)