That's what I meant by the Macbook and the printer connecting to the same AP. The Pico is the AP, and both your printer and the Macbook connect to it. (You could also use a cheap off the shelf travel router)

What the Macbook can't do is have multiple wifi connections at the same time, so you'd have to disconnect from its primary network (which also rules out the Macbook serving as an AP that the printer connects to).