CRISPR is cool, but isn't the challenge of adult genome editing bottlenecked by the delivery vehicle? Last time I checked it's still hard to deliver viral vecto

CRISPR is cool, but isn't the challenge of adult genome editing bottlenecked by the delivery vehicle? Last time I checked it's still hard to deliver viral vectors past the blood-brain barrier. Does CRISPR have a unique solution to that? I also would imagine that a "BCI" optogenetic adapter would be so massive that payload size alone (never mind electric properties) would never make it past the BBB.