Yes it is possible to complete this optional objective. I just did it.
As you know, there are incendiary barrels nearby. There is even one right next to the jump pad you are supposed to use, facing the basketball net (the same one the other guy used).
So, I shot the barrel while standing next to it, which lit me on fire. I then immediately moved to the jump pad, which propelled me to the basketball net. I don't recall if you need to also use an oxygen boost to get as far as possible; use it if necessary.
But, I think the key is to always be looking down, because once you are almost above the basketball net, then immediately crouch to slam down onto the net. This got me both the optional and primary objectives.
Although to clarify, the secondary objective of lighting yourself on fire marked itself as complete for me immediately once I launched myself into the air, so even if the fire goes out, I would imagine you already get the objective anyway since it's already been marked.
According to the wiki, you need to input specific recipes into the grinder. The recipes, are as follows, and require items of the same rarity in every case but the legendary case:
- Legendary of desired type: 2 legendary weapons + 1 purple weapon of the desired type
- Up one rarity level (specific type): 2 weapons of the desired type + 1 other weapon
- Up one rarity level (any type): 3 weapons of different types
- Up one rarity level (non-weapons) 3 items of same type (grenade mod, shield, etc)
- Assault Rifle: 1 SMG + 1 Sniper Rifle + 1 Shield
- Rocket Launcher: 2 weapons of any type + 1 Grenade Mod
- Shotgun: 1 Pistol + 1 SMG + 1 Shield
- SMG: 1 Assault Rifle + 1 Pistol + 1 Shield
- Sniper Rifle: 1 Assault Rifle + 1 Shotgun + 1 Shield
For all except the legendary recipe, these recipes work for anything up to and including blue inputs, with the potential to output a weapon of the same rarity or greater. If fed moonstones, the grinder will always output an item of increased rarity, and has a chance to add a luneshine effect to the weapon.
Best Answer
According to the internet, a Badass rank of 2,500 is required: