To add another good experience to the list: I originally bought a Renkforce USB/mSATA-Converter Shield for my Pi3b, but before I set it up got my hand on a Pi4b instead. The Pi4 runs in a passive-cooled Flirc case (temperature usually between 40 and 44 celsius), and the renkforce board sits on a self-cut acrylic board on top of the flirc, with a cover over it, and works really fine with the Pi4. Connected it to a USB2 connector, and used a transcend 128gb msata SSD in the adapter board.