Considering determinism as harmful or destructive is giving it too much power. I don't think it's such powerful concept. If this is fallacy on my behalf, feel free to point it out but let me explain how I see it.
From Epicurean perspective, wouldn't it be more accurate to consider determinism similar to death? These should be nothing to us as we simply cannot experience them.
You mentioned that '[...] the world revealed to us by our senses / feelings / prolepsis is the only one we have, and the only one we are ever going to have [...]'. I see it exactly the same way. As humans, we perceive time linearly. There's no other way for us. Therefore, it doesn't make any difference if the world is deterministic or non-deterministic. We always experience it in non-deterministic way. Whether free will is objectively true or not, it is true to us. Even if we are automata, we're not able to experience autopilot mode.
To be clear, I'm not advocating for determinism. Not in the slightest. I'm just making a point that determinism seems to be like death. These concepts can be harmful only if we allow them to be by thinking about them in a way that make our lives unpleasant. In reality, we all experience free will in our lives. Then we die and we don't.