Magnetic reconnection and the strorage of an ultra dense plasma matter in a magnetic confinement would be the ultimate power to go where no man has gone before, deep space far far away.
The attraction of sailing has always been the lack of propellant mass required. While the acceleration is low, it is constant and long-lasting, permitting high velocity over time, riding a laser or (e.g.) diffraction-lens-focussed beam.
I suspect that at human scale, “storage of ultra-dense plasma in magnetic confinement” is going to require more mass and power than can be managed. It is also inherently risky, as the failure of confinement leads to very nasty local effects.
The genius of FF is that it uses natural magnetic effects and processes at sub-microscopic scales to achieve strongly positive energy payoffs, not hard-driven superconducting magnets. And the local dangers are minimal by comparison; there is some toxic gas (decaborane) involved, but no particular explosive potential to breach containment.
From what I know graphite is a material that can withstand extremes in pressure where other materials would incinerate or become liquid. Instead of shattering, incinerating, or melting like most all materials a graphite and carbide could be Incorporated in a organic composite material that can sink the extreme heat and withstand the fluctuating pressure. The next step would be to redirect it.