I have a small shop (no remedy) and vasomotor rhinitis (no cure). My sinuses and nasal passages are hypersensitive to various stimuli including the ultra-fine dust created in a woodworking shop. Oil-burning exhaust, perfume, cleaning solution oderants, cookies baking - all sorts of things that most people aren't affected by (I know, some of them smell good) are like snorting battery acid to me.

A fair amount of the culprit particulates that get to me are too small to be trapped by the typical shop dust filtering systems that I have looked into
(also, most of these systems are simply too large to be installed in my small area). So I am considering one of the larger consumer "air purifiers" on the market. Any comments or experiences?

The HEPA filtration that is a part of these units would be a plus point for me but I am a little skeptical about the capacity of the filters in these units when put to use in a woodworking shop. Any discussion of the limits of these filters?

I do use a P100 mask when I am cutting and I use vacuum dust collection on the tools but that doesn't catch a lot of this fine stuff and I don't want to have to wear the mask full time in the shop.

IMHO it would be a costly exercise that will not do the job. The real solution for you is to prevent the fine dust from becoming airborne, otherwise you are going to be breathing it until the room filter captures it. The air purifier will capture the fines but will clog quite quickly and as you know the price of HEPA filters for those little guys is high. The idea of capturing all the dust before it becomes airborne is a worth target but never really achieved. In my shop I have a Oneida cyclone dust collector plus a 1350 CFM air filter and some dust still makes it up stairs to the living area where I have an air purifier. I think the solution in your case might be a battery powered air purifying respirator. The better ones are not all that uncomfortable to wear for extended periods.