RefreshAccess Usage

Do you know if there is any detriment to calling RefreshAccess on the Storage Cloud controls (dropbox/google/box/onedrive/amazon) before each and every file upload/download if there are many files to upload/download?

It's kind of tricky to calculate the time left when you don't know how long the transfer will take.

We were doing a download of 1000's of files, and some of them ended up as 1k files, which basically contained the JSON return stating that the token was expired.

Also, this brings up the question, if for example the token has 30 seconds left and you start a transfer that takes 60 seconds, does the api let you finish?

It is safe to call RefreshAccess before starting an operation.
As far as I know, only Google has this 3600sec limit but if you refresh it for every transfer, it should be safe, unless your transfer will take longer than 60 minutes.