Oh just butch up and use a converter, maybe even LEARN to convert in your head. Ya, I use SAE normally and the biggest reason we don't convert to metric in America is that it would cost about a billion dollars in road signs alone, BUT we're on an individual level and as modelers, we should be a cut above. We're creating here. You don't want to convert, go buy a plug and fly and be blissfull. You want the challenge of a build, learn to use ALL your tools. Specially that one between your ears.
This is actually the first time I've had this talk from the SAE side. It's usually some wanker complaining that Merica don't use metric. Kinda fun