Consequently, you have to swing the angles to weird things like multiples of 7 or 13 degrees to prevent that. If traces are small enough that they fit between the PCB weave, different traces can have enough difference in electrical permittivity that it will screw up the matching (trace 1 has an FR-4 fiber directly underneath while trace 2 only has cross fibers underneath and so has about 50% air underneath instead of 100% fiberglass). In fact, the only good argument for using non-Euclidean traces is in the ultra-high-speed arena (think DDR4 bus or multi-GHz RF). All for effectively no benefit on 99.9% of all PCB designs. You have to operate control points for every single segment rather than just dragging a trace. Ever tried to manipulate font outlines? It's like that on a PCB, only an order of magnitude worse. Curved traces make your GUI ridiculously unmanageable. Aside high frequency busses (which you're doing EM analysis on anyways), traces can be all sorts of shapes. Well, to be fair, the 0/45/90 deg traces are a byproduct from early days of EDA CAD products.
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