This is very likely wrong, all of it.
Well save for the fact that Siouxsie is correct in that this manufactured RNA heads to the cytoplasm that’s about all that she’s right about in these tweets.
This man-made RNA likely doesn’t break down as easily as natural RNA. Why? Because it has been engineered to be a little more persistent so that it will reach the cells before breaking down. And the lipid coat is not there to break it down or destroy it but to make sure that it attaches to cells, like attracting like. What does this mean? Although the jury is still out, it’s likely this RNA ends up changing your DNA due to its man-made ability to persist.