There's no difference between SE & Pro in this respect.
Bear in mind that this only affects the actions of the profile if something else is running with a higher priority. It's also (as per the Help) not recommended to use Idle.
But it sounds to me as though you may have hardware issues if this just started happening (so that it is the attempt to address the new drive/s that is causing the issues). Bear in mind SE/Pro neither know nor care whether a drive is USB1/2/3 (or even if it is USB at all) - we simply pass the drive-letters\paths\filename to a Windows API and say (in effect) 'copy that from there to there, please'. Windows does the rest - we don't interact with hardware or drivers at a low-level.
Try a test profile of some example files to a dummy folder on the old drive/s (USB2?) and the new drive/s, and check the performance...
Note: you don't actually say if these USB3 drives are actually connected to a USB3 port? I can also tell you from personal experience that doing so doesn't always get USB3 performance...and it may be if you have driver issues (or are using a hub...) that you are encountering problems when you try.
Bear in mind that this only affects the actions of the profile if something else is running with a higher priority. It's also (as per the Help) not recommended to use Idle.
But it sounds to me as though you may have hardware issues if this just started happening (so that it is the attempt to address the new drive/s that is causing the issues). Bear in mind SE/Pro neither know nor care whether a drive is USB1/2/3 (or even if it is USB at all) - we simply pass the drive-letters\paths\filename to a Windows API and say (in effect) 'copy that from there to there, please'. Windows does the rest - we don't interact with hardware or drivers at a low-level.
Try a test profile of some example files to a dummy folder on the old drive/s (USB2?) and the new drive/s, and check the performance...
Note: you don't actually say if these USB3 drives are actually connected to a USB3 port? I can also tell you from personal experience that doing so doesn't always get USB3 performance...and it may be if you have driver issues (or are using a hub...) that you are encountering problems when you try.
