Maybe it would just make more sense to invest in tech stocks in general. While one is not getting much of a speed up on each roundtrip, multiple roundtrips, doing a little calculation on each trip, sounds like a major engineering task and not a fundamental task. And if that works, then we get the usual speedup - NP to P or whatever the precise complexity class conversion is, which sounds very economically valuable and whomever maintained the FTL computer would be able to extract much of the surplus.