If he has a small (~1 square cm) mirror, which is all that's needed but keeping in mind that he needs two of them, one for vertical deflection and one for horizontal, the mass will be nearly negligible, considering that the head stack and levers can be deleted from the mechanism. That mechanism type is fast enough to allow for a rasterized display projection, as it can operate in both directions at equal speed.

The real challenge is in manufacturing a fixture in which the alignment of the two mirrors with the laser source can be practically supported. Since both the incoming and outgoing light levers will be quite long, precision of manufacture will be a critical requirement.

As it happens, HDD head positioners also swing about 40-50 degrees. You don't suppose there's a reason for that? No matter whether he uses a stepper, or a voice-coil head actuator, both are angular options.

RE