Change file/dir masks "on the fly"

Hello. I have a bulk download, when even scan of the remote directory takes a while (several hours). After the background download started, I've found that some files must be ignored. Can I change the file download mask without canceling the current request? I need only add the Exclude mask?
By the way, is it possible to view the current mask settings of a background request?

No, it is not possible.