Yeah, but that doesn’t matter here: we already counted the 10 when they bought them. So when we subtract the 10 because they’re imports that doesn’t mean importing a lot will lead to a net negative.
If a company 10x their imports to get ahead, we’d count the 100 worth of buying, and then subtract 100 because that was all imports. You still get zero effect on gdp from the import itself. Which is correct.
The point of the subtraction is to make imports zero impact, zero impact when big, zero impact when small.
I've seen this in coffee - roasters buying a year's worth of packaging.