There's several ways to skin that cat. The least waste of material is to forge it round, twist, then forge flat.....being VERY cautious about doing so at welding heat. If you try to move too much material, and let the heat go too cool..... that's when the cold shuts happen..... and they happen at any sharp angle that is twisted. Speaking for myself, I anticipate/expect at least some cold shuts in twist patter along the edges, it's just part of making twist patterns.
I've always found it interesting that most who've never done it, think of "twist" damascus as on the of the "easy" patterns..... When in reality, it can be more frustrating then some of the complex mosaics.