I'm still farming Umbrite for my first Anima. I doubt if I'll finish before 4.0 (even though, as I understand, this is the grindiest part). I may take a weekend and just chain Aetherochemical Research Facility to finish this part, but then comes more grinding.
Honestly, these weapons reward diligence and persistence more than anything. They're a really long grind that only pays off if you're extremely diligent with it. The "fun" component relies on your ability to enjoy playing through the same content on repeat. If you don't love your job, and if you don't love the content, you'll burn yourself out on it.