If you have Beidou or Yanfei, you need to collect Noctilucous Jade for their ascension phases. Otherwise, there's no crafting recipe or weapon's ascension which uses Noctilucous Jade. So, you can farm it according to your time and don't need to worry about stacking them in abundance. However, I'll still recommend you farm a couple of them extra to be on a safer side. That's because it may be possible that some new weapon or character launches in future Genshin Impact update and use Noctilucous Jade for ascension.