[atoav]

I work a lot with wood in the metric system and the third thing is bot a problem at all. I never had even remotly any trouble finding 333.33 mm or a 666.66 on a tape measure. For anything that needs extreme accurcay I’d go with my iron ruler with 0.1 mm ruling and beyond that I would go for a caliper.

If you consistently have to use a weird measurement over and over again, you usually end up making a temporary ruler (paper, wood, metal) anyways