For the sake of future people looking for the modding tools, here:
https://drive.google.com/drive/folders/1p5TVjhP0MgwYDuBWUWxjOf8Js0ErVYtU?usp=drive_link
It includes Zindea's older Quest Editor, their most recent updated version of the editor, Gougout's Editor, and Zindea's MH3U Modding Tools. As well as Citra mod pack to allegedly allow for 60FPS and fix the Charm Table nonsense that 3U has.
The modtools here were designed for use on WiiU MH3U, however it is possible to use Zindea's quest editors for 3DS event quest files.
Must be placed in the same folder as your event quest files i.e. "quest1", "quest2" etc.
Gougouts Editor is immediately flagged as a virus. I'm 99% sure it's perfectly safe, though it is all in French. It uses Cheat Engine.