A few hours later, the store responded saying can you please change the reason to "no longer needed", that way the refund will be processed faster. I already had the return label at that point and couldn't change the reason for return. Told the same to them and no reply after that. Just gonna ship it and see what happens.
I think that's more to do with their internal rating with Aliexpress, than a faster process.
If it's something wrong with the item they maybe get 'punished' in some way by the platform, lower rating, maybe makes more difficult to hit some target of sales and ratings.
Instead, if you say it's 'no longer needed' the return and refund happen normally but the store's reputation remains the same.
at least for some cases, because I know that some items have the 'return in 15d' tag, and I remember reading that you can return whatever the motive is, it's not required that's some error or defect on the product