To connect multiple cameras in a single usb port, multiple USB hubs can be used, which can be connected in chain, using a single USB port maximum 127 camera can be connected. Highly recommended a good quality USB cable and hub usage.
Isn't possible to trigger cameras in same time using just a usb connection, will be a lag between camera captures around of 200-800 ms so if you use 10 camera the time difference between first camera capture and last camera capture will be 2-8 seconds, this lag isn't the application limitation, this is limitation of the USB hardware. To get acceptable result a external trigger device should be used. There is multiple possibilities like Arduino or USB relays. For configuration check the Settings->Devices page
For better workflow it is indicated when capture in progress to set the transfer mode to camera only and after session finish download photos to pc, from download windows all photos from all cameras can be downloaded with a single click
To download photos from multiple cameras, it is indicated to uncheck Load thumbs in download window this will improve the file list loading time.
For Canon cameras if you experience program hang on startup, start the application without connected cameras, go to File->Settings->Advanced and uncheck the Load Canon transfer mode
To download in separated folder by index (capture order) from multiple camera
Can I connect all cameras by usb with usb hubs ? how many PC have to use for connection ?
Can I trigger the shutter to take the photos by your software as the same time ?