I didn't find mention of '2 micron' particles in that document - https://www.epa.gov/sites/production/files/2014-07/documents/aircleaners.pdf
Perhaps particles that large settle out of the air before reaching the filter - so they are still 'in the room' and haven't been trapped by the filter.
We are satisfied with a single room Honeywell air filter that has cleanable filter (cleaned by removing and vacuuming the filters).
If you use a vacuum cleaner for removing dust - be sure to use good quality filter bags (I prefer bags from the maker of the vacuum), and check the condition of the bag to make sure it is not damaged or full.
We do use a vacuum cleaner, but dusting clothes (e.g. Swiffer) work quite well on solid surfaces, and work by holding the dust on the cloth instead of making it airborne.
There are several good 'anti-allergy' products available - the newer ones might only require 1 per day. I use a 1st generation antihistamine called Chlorpheniramine Maleate 4mg (ChlorTabs). It's 'take as needed', 1 table every 4-6 hours. It's been around for decades and has very few side effects, and has been shown to be safe and effective.
Endwell NY USA