[teensy4] Why does USB_MIDI4 expose fewer USB endpoints than USB_MIDI?

[forderud]

The teensy4 USB_MIDI4 configuration appear almost identical to USB_MIDI, with only the following differences:

• bcdDevice is explicitly configured to 0x0211 with a BCD_DEVICE define
• Slightly longer PRODUCT_NAME/PRODUCT_NAME_LEN
• NUM_ENDPOINTS increased from 1 to 3

What puzzles me is that the USB_MIDI4 configuration reduces NUM_ENDPOINTS from 4 to 3, compared to the USB_MIDI configuration. I would intuitively think that the number of endpoints should remain the same. Could this possibly be a bug, or am I misunderstanding something?