I also interpreted it as some American playing around with metric units while ignoring already established conventions so I went a little bit extra for emphasis, although it might have come out as rude, sorry.

Thanks for the apology, but the agro isn’t warranted for something like this imo.

Given how few of us Americans bother to try to use the metric system, I’d say go a bit easy on us when we try to use your system. No sense in slapping someone away from trying when they don’t know the established conventions, especially when there’s no harm to come of it.