1) the uncertainty of momentum for such a high planck constant might cause the seeds to spontaneously fire out of the melon, or perhaps if mass is measured to high degree then a severe uncertainty in time is present and the seed might go back in time and kill your grandfather
or
2) the melon's own blackbody radiation would then be strong enough to not only pose a severe radiative hazard on par with super massive black hole accretion radiation, but the h2o inside would be decoupled releasing toxic levels of oxygen into the near vicinity, also posing extreme fire hazard
or
3) warped planck constant is indicative of extremely curved universe where the melon and only the melon can possibly exist making it some sort of deity
conclusion; transdimensional melons are dangerous and probably not delicious
