The craftable Droden weapons are level 6 (the vanilla max level) by default, so no need to upgrade them. Randomly generated weapons, like the violated versions of Droden weapons, can't be upgraded, but you can find higher-level versions if you find them on higher-level planets.

where can i find higher level violated droden? the only ones ive found were on desert and savannah planets, which are low and moderate-level respectively

引用自 Nameless Nate.j2：

where can i find higher level violated droden? the only ones ive found were on desert and savannah planets, which are low and moderate-level respectively

The random encounters with Violated Droden are only found on desert and savannah planets, but they are optional targets for the randomly generated quests offered by NPCs, too. Look for NPCs on higher-level planets (their race doesn't matter), and they might ask you to eliminate a group of Violated Droden.