Hi 0xc0170, 
For your second question, I've already done in the latter way. That is if the user connect more than one board at one time and don't specify the board_id with -b option, the pyocd will firstly list all boards connected, and then ask them to input 1,2,3... to choose which board they want to connect.

The reason I think we don't need to accept the "-b 1" option is that, usually user can't make sure the sequence of the board listed in the usb devices list(for example the first board in the list may be out of power and the number of it will change when it reconnected to the usb, but it's easy for user to think that it's still the first board in the list). So "-b board_id" will be more clear, and won't make any mistake.