I think you're doing fine. Nothing will support the floor like a wall. I have seen often, that a main girder will run down a hallway under one wall, and the wall on the other side will still have enough load to cause the joists to sag 3' from the main girder. Support issues will drive you nuts. Most building inspectors and firefighters hate those basement jacks. Be careful using them. When you raise that big jack in the center, the two basement jacks could fall on you.
Be extremely careful, this is the kind of work that can get you seriously hurt.
Oh! welcome to the forum Nathan.