It all depends on how easy you want the user to make the selection...
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Zero ohm or two pads close together require the user to have basic soldiering skills and access to those tools...? Do you really want it to be that hard to make a selection?? If/when they lift the pad(s) or lose the resistor before putting it back they are dead in the water...
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I use combinations of 2-pin, 3-pin, and 2x3-pin headers and shunts so the user can add/move or remove a shunt to make a selection...? 99% of the time I use 100 mill headers but have been known to use the smaller metric ones when space is tight...
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On the last page of my schematic, I have a dummy part for each color of shunt and how many are needed...? It is embarrassing to have a build of PCB and you can't ship them because you forgot to order the shunts...
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Dallas N4DDM