[snakes1100]

The amount of data a script imports or the amount of time a script runs for is based on your servers php settings, some mysql settings can also be changed to hel pas well as limit what the db itself is using, not Impex.

If your on a vps/dedicated server those are easy to change around, if your on a shared server your going to be limited as to what you can change, most hosts allow for a local php.ini in a customers account to change most settings of php for that user alone, they most likely allow php flags in a htaccess as well for making those changes, but your not going to be able to change any mysql settings.