Hi there! I've some questions about preferred region. I'm making a website for Brazil. There's this variable that I can export called preferredRegion. I put it as 'gru1', which is from São Paulo, Brazil. But even though I did that, I've just found out a Functions settings in Vercel about serverless function which wasn't 'gru1' even though I've set preferredRegion as 'gru1' on the root layout.

First question: the preferred region exported on root layout will set what exactly if serverless functions are configured elsewhere on Vercel platform? What's the difference between these two?

Second question: I've to get some data from Amazon from time to time (not sure yet the frequency, it might be something like 4 requests per page per hour (making the cache revalidate after 1h; I have 5 pages). It seems that the Amazon that is stored in 'us-east-1'. Should set preferredRegions and/or Functions in Vercel as Brazil or as US East? Which one is better and why?

Third question: My idea is to get the Amazon data on React Server Components (RSC) using fetch. Is that considered serverless function? Which configuration is related to that: preferredRegions or Function settings in Vercel?

Thanks in advance!