Boundaries as In I don't want them coming up there with a gun and shooting the crowd...yeah there should probably be some limits to what they can do and say. Comedians like all humans, should have a filter and know when something is pushing it too far. If a joke is funny to 8 people and offends 8 billion, it's probably too far. It is amusing, when one group will say yeah that black face joke is hilarious whats the big deal, and than throw a fit over the christian joke or someone poking fun at their political hero.

In seclusion I suggest a boundary that doesn't impact a maligned population. That is to say if you only have 1 joke about a group, don't make it about people that are already shit on by society at large. If you are targeting everybody, go for it. But be ready to accept consequences too. They used to say, "Know your audience" but with the advent of the Internet and social media, your audience is everybody now.

That said, I now personally only joke about straight, white males because nobody is more sensitive.

Should this boundary be a legal, or personal moral one? Who would implement this? And what if a historically marinated group is currently causing a lot of problems and needs to be made fun of? I didn't mention this in my last post but a big purpose of comedy is to help society deal with issues and help it figure out who is right or at fault. It does this by reflectively poking fun at a situation or making fun of an offending party. However, any kind of hard boundaries would destroy this, and hurt comedy's ability to give us a nuanced perspective on life.  Just some thoughts,  sir. You had some good points, but not sure if you thought broadly on all of that. 

So what people are shit on by society in large? I think thats just opinions at this point. You might think one group is being shit on alot and another might think a different group is being shit on. And so comedians cant joke about anyone.

I mean who would be in charge of who comedians cant joke about?

Short of them waving weapons on stage or threatening violence (that starts to become clear it's not a joke, but it takes a long time to figure out sometimes) there shouldn't be legal consequences no matter how hateful or edgy their jokes are.
But I think venues and companies firing or reprimanding comedians if they feel they go too far with certain jokes about race, sexuality, gender identity, etc. is fair game in terms of legality. 
If a comedian wants to voice bigotry in a way that is in poor taste or not comedy at all, they shouldn't expect to be welcomed everywhere with time and money. They can use their freedom of speech to express that in videos, public streets/buildings, etc.

As someone who dabbles in stand up, to the best of my knowledge, there are no limits on what a comedian could say beyond the normal limits on speech (threats, defamation, etc).

That being said, your job is to be marketable. If what you say causes people by and large to dislike you, then you're not doing your job very well. And it is perfectly reasonable that people may not want to work with you.

In the end its about putting asses in the seats. You can say pretty much whatever you want as long as you can still accomplish that. George Carlin, Joe Rogan, Dave Chapelle, Bill Burr, Louis CK... all of them upset a whole bunch of people. Still all getting well paying work. I mean... aside from George Carlin. For all the concern about it, I'm not sure I recall anyone being actually "canceled" unless they do some Cosby level shit.

Yes. If your type of comedy consists of spreading hate speech, raise social suspicion against marginalized minorities and soften ideas that go against human rights, you should suffer legal consequences. There are comedians who seek to do all of that as a priority and have the laughters as an ocasional and mere consequence. I've seen a lot of people saying a bunch of crap and trying to get away with it by basicly raising a "it's a joke" sign. What a lot of people don't understand is that words aren't merely a bunch of sounds, they have the power to affect the world, specially if you have a whole audience listening to you.

So which comedians do you think should face legal consequences for their comedy?

No. Most comedians understand the limits they are able to push, and if don't, they will learn it the hard way. They don't need someone telling them what they can and can't say.