I fell into the Borderlands 2/TPS modding community in early 2018 and have yet to extricate myself. I've got a number of BL2/TPS-modding-related things hosted here, so here's the list:
- General Modding Info for Borderlands 2 / TPS on Linux.
- A BehaviorProviderDefinition and Kismet Sequence Grapher, to aid in modding those slightly-more-complex-than-usual objects in the game.
- BPD Number Calculator, again for use in editing BehaviorProviderDefinitions.
- Borderlands 3 Object References. There's currently (as of October 12, 2019) no real modding for BL3 yet, but a certain amount of data introspection is possible, and intrepid and tech-savvy users can technically inject hotfixes, at least. This page will let you look up references between BL3 objects, which may help to shed some light on things, or just find objects you're looking for.