Builder's Bag is a relatively new mod that offers many quality of life enhancements for building with numerous mods.

The most significant improvement for Omnifactory would be the crafting and chisel modules. For anyone making skyscraper-sized buildings out of chisel or ztones blocks, the ability to stockpile ingredients that can be crafted into chisel blocks and chiseled into the desired block without requiring repeated use of the chisel UI would be a welcome improvement.

The randomness module offers the ability to put down randomized chiseled or other blocks, and the middle-click pick-block support is also potentially a very welcome option. It also includes a LittleTiles module, though I don't have enough familiarity with the mod to know how much of a difference it will make.

I believe there may be a forge-based compat issue but this is speculation. I've got a ticket open on builder's bag project