We've researched sun tracking vs fixed angle installations deeply in the early 2000s. Our conclusion back then was that sun tracking was not worth it for us mainly because we could not produce it both cheaply enough and make it reliable over the projected lifetime enough to not eat the additional profits from the better yield of tracking.

The bi-facial vertical solution seems to be similar in spirit. Forgo the theoretical additional advantage of better angles for higher reliability (no sweeping required).