It’s always good to be cognizant of trace lengths when you’re laying out a parallel bus, though at moderate frequencies it is nothing to stress about. The propagation time for a signal traveling through a trace is maybe 150 picoseconds/inch. So if you have two traces with a length mismatch of one inch, one signal will arrive 150 ps after the other signal. If your signals are transitioning at a frequency whose corresponding period is much greater than 150 ps, this one-inch mismatch won’t cause problems. Even at 100 MHz (which is pretty fast for a parallel bus), the period is 10 ns, i.e., ~67 times larger than the time-of-arrival discrepancy for a one-inch mismatch.
Automatic machines translate to added costs and some such as the depaneling router creates vibrations, noise, and vast amounts of dust. In addition, you need to hold the board firmly. Although laser cutting is precise and has less mechanical stress, it is capital intensive and only applicable to board thicknesses of around 1 mm.
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