Can multiple devices be used at the same time?

Yes. Each adapter enumerates as its own USB device (HID on the Supernova and the Pulsar, a COM port on the Nova), and each has its own serial number.

Mission Control 3

Every tool tab has its own device selector. To work with two adapters, open a tool tab for each and choose a different adapter in each tab. Several tabs can also share one adapter.

In the web app, an adapter can be open in one browser tab at a time. Open the tool tabs inside the same browser tab.

PyCosmicSDK

list_devices() lists every connected Supernova and Pulsar with its serial number. Device.open(serial="...") opens a specific one, and several can stay open at once:

from pycosmicsdk import Device, list_devices

for found in list_devices():
    print(found.model.name, found.serial_number)

with Device.open(serial="<first serial>") as a, Device.open(serial="<second serial>") as b:
    ...

See the PyCosmicSDK documentation for list_devices() and Device.open().

Binho Nova (legacy)

With Mission Control 2, launch one instance of the app per Nova.