Welcome to SR!
Lots of good advice above.
If he is smoking crack, he is going to spiral down. I'm a recovering crack addict, and that demon drug totally takes over your life.
You don't have to justify why you have "a problem" with his use. What he is doing is illegal, putting the safety of you and your children at risk, AND putting your freedom at risk. If you know he's doing it, he gets in trouble with the law and your kids are around, you can be charged with child endangerment.
He may be working and paying bills now, but I assure you if he keeps it up, the money he's making is going to go toward crack. As soon as you smoke it, you want more.
In all honesty, I would be putting money aside that he has no access to. I'm not trying to scare you, but I've seen people post here that have literally smoked up a million dollars in crack. If I had saved the money I spent in a year, I could have paid cash for a house.
I hope you stick around, read the posts, and put the focus on you and the kids. He's going to do what he wants to do, and that sounds like he wants to stay high. Dope, of any kind, doesn't "take the edge off"....it puts us in denial of reality.
Hugs and prayers!
Amy