Turned up today. Soldered some headers on in around 5 minutes. Plugged it in - was recognised as 4 serial ports straigh away.
Connected to 4 instrument ports and happily showing me diagnostic information. Takes up a hell of a lot less room and cabling than the old setup of four separate adapters, and they have also been repurposed for other projects now.
I saw the Quad Serial and thought it would solve an immediate need: my laptop has limited USB ports and I need to connect multiple devboards at once. FTDI makes a breakout board but the Quad Serial has much nicer form factor. Small plug (kinda): I made a simple 3D-printable base board for this part: https://www.thingiverse.com/thing:2131515