Can you add an option to opt-out "forcing all API call in mainthread", it hurts performance a lot

Did performance testing after forcing all API call in mainthread, 40% worse

I know there will still be some room for optimization. 

But it is also not surprising that making all API call in main thread will decrease the performance.

Just like database have SERIALIZABLE but no companies in practice actually use it when they scale.

IMO this does not only hurts performance, but also make programming harder. One need to keep thinking about which thread the API is calling from, istead of just calling the API originally