IMHO the key thing is to fully grasp the rules about your area and then circumnavigate em. Yeah if your in the middle of a HOA or similar bullshit your probaly screwed but for most of the rest of the world you can get away with a lot, so long as YOU DO NOT cause annoyance to others or fly to many red flags!!
If you want to do heavy machining - fab your going to have problems, the diesel forklift idling is going to piss people off as will the HGV deliveries.
On the other hand if your near silent, don't have large deliveries, don't have engines in anything parked out and idling and keep the customers desecrate you can get away with a lot more.
Just because you have a lathe and cnc mill + welding gear does not make you a heavy industry at least not around here. You can be a artist, you can offer electronics repair or light custom component prototyping - sewing machine repair or any other crap thats not going to cause any inconvenience to anyone else you can imagine. Key thing is not to be a machine shop, not to fall into the usual typical categories. Now your sewing machine repair shop may currently be using the machines for makeing something else as works quiet, but hay mans gotta earn a living.
Soon as you start asking for code acceptance your on the radar. Cause no harm, don't fall fowel of things and your light years ahead.
Here in the uk once you have been doing something for a decade at a location your sorta grandfathered in. Still can not cause a nuisance, but you have a lot more wiggle room.
On the 160 home street i live on theres at least 2 landscape gardeners with multiple vans, a small part time printers, a UPVC window fitters yard, a guy making wood bowels at least semi commercially or he uses em as disposables to eat with!! At least one canabis farm that had been running for a long while till it got raided, various people working from home in the IT sector and a fair few others that also do stuff. No one batts a eye lid about it. The only thing that everyone’s pissed about is the next street over who race stock cars at least semi professionally and are revving there engines most days.