Thats all sorts of wrong (not you, them making nanite behave like this).
Disabling fustrum culluing is not the answer either.
Having a system that realizes any percentage of the tris is still within the fustrum and should therefore not be culled is sort of a huge must…
They could do even better by allowing bounds you can set to expant or contract the default camera fustrum…
In like 10 minutes of work probably, if the right guy looks at the file…