I did not find this to be the case, except with a few low quality vendors we ended up dropping.

It was mostly the same as anywhere else, you go talk to them in person, tour their facilities/processes, and see what else they've built.

I was warned strongly about IP theft and cost cutting, but didn't find that expectation quite met reality. It may have been that our products were mostly un-copyable, and we specified everything precisely, or were just lucky.