In general I agree that go one size bigger on the VFD, if the price difference is not significant. Given that the NES1 is a budget VFD, I assume price was an issue. I often see a significant price jump from 1 to 2 Hp units, in this case it is another $40+ to size up. On the other hand I did a 3Hp motor with 3 phase power installation with a WJ200 and opted for the 5Hp VFD because the price difference was nominal. I also considered that the machine might be replaced with a larger 5Hp unit at a later time. You will not get any performance difference between the two, and it is unlikely to see any difference in parts longevity, as the VFD will be obsolete by the time it fails. If I where in a very hot environment, continuous duty at close to full load, then I think one could make an argument to size up based on the VFD components not being stressed to their maximum ratings, and the capacitors in theory should last longer. That being said, on my new 3Hp (Acra/Sharp) mill, the manufacturer undersized the VFD. The manufacture says they have no issues, Yaskawa tech said it is not rated for a full 3Hp in the wired configuration. Given that the load is usually way under the full potential of the Hp, and it is not being run at full Hp continuously, I guess they can get buy with a smaller VFD.
I usually do VFD builds where the VFD is integral with the machine control system, so unlikely to be re-purposed at a future point. They are not very expensive in the 5Hp and under size, and the technology is evolving, so kind of a moving target on whether to reuse an older VFD or just buy a new one. Also, per the manufacturer's guidance, if you up-size the VFD, the input wiring, fusing, switch gear must be rated for the VFD rating and not the motor rating.