Interesting, though I would like to see more cost comparisons.

Some negatives I've found are UHV lines used for renewable transmission will see low utilization and the switching equipment is quite unreliable so overcapacity is needed.

I did find a book with some details in case anyone wants to dig deeper: Ultra-high Voltage AC/DC Power Transmission (2018) (http://gen.lib.rus.ec/book/index.php?md5=7AF7982201735A290D8...)