I'd imagine this is the easiest solution for improving mission flexibility.

If the only rules are "only accelerate away from the nearest star", that doesn't preclude using a planetary gravity field to also adjust your orbit.

E.g. Making small course corrections in interstellar space (or simply mission planning exactly enough) so that you hit a planet's gravity well on insertion into the destination solar system, thereby slinging yourself into a more manageable eliptical orbit (and potentially burning something else at the right point to change your orbit)

I'd also be really curious on how something like this works in the area of interaction between a planetary magnetosphere and the "sail" (e.g: https://en.m.wikipedia.org/wiki/Magnetosphere#/media/File%3A... ). Looks complicated!

The field generated by the drive is in the realm of 50 nanoteslas, and Earth’s geomagnetic field for example is in the microtesla range. I don’t think it really matters though, because the magnetic field around a planet redirects solar wind, and that alone would be enough to screw up this drive. In my opinion this is something you use for the interstellar leg of the journey, and you would avoid planets while the drive is on. That isn’t really a problem though, because other than a relatively short trip away from Earth, you’d be avoiding planets and building up momentum. To make this work, you’d be going at a hell of s clip relative to any other planets you’d come across, and you’d be a tiny mass to boot.

You’d probably just sail on past, with a deviation in course, but not orbit or a 180. For any gravitational maneuver, you could rely on momentum and shut down the drive, restarting for the return leg.