Here in Michigan, they have the right to inspect all taxable property, inside and out. If they want in or on they just call in the proper paperwork. Most of the time it's the neighbors that start the initial call. And all that is, is some stupid yuppie that didn't like what they seen when they drove by. There are already people that drive around the burbs looking for smoke. I'm sorry that's more like riding their $10,000 bicycle in the middle of the dirt roads in the country. Upper macomb and Oakland specifically. I guess the multimillion dollar paved bike trails aren't good enough for them.
It is a sad shame, but their is also a law that allows you to build items that don't meet code. The Home Depots sell lots of plumbing and electrical parts that don't comply. I don't know if this will apply or not. You can't pass a law to put someone out of business. Being licensed is where you have less say, yet are more liable. A handyman is not , as far as trades go.
I don't know if I would get too worried about whether they will still be built. There are many wood burning devices that have and do already comply with the low emissions and particulate. Cat stoves, lambda controlled wood boilers, and a few gasification boilers. It might actually bring the price of those down if they all have to have that to be clean. Heck a lot of these OWB's are burning pretty good results in the lab, if they can improve operator in field performance then it might not be all that hard.
I still despise market manipulation , treehuggers, and liberal morons that squeal so much and push politically correct trash into law. When in many cases it never effects or applies to them. I'm sure many of you have read some of the stupidest comments on youtube OWB videos from said cidiots,treehuggers, libs,etc...