I am not sure if anyone has stated this, but these may not even be rank 50 NM's. Yoshi did mention awhile back adding lower rank NM so we may even be seeing those. As for spawn times I do agree they need to be longer, but not 24 hours. A 8 hour with a 30 min-1 hr window would be plenty for me, or maybe spawn conditions like dodore where it has to be certain weather to, if these will be rank 50 ones. Just my opinion, but I really dont even think these will be rank 50 ones.