Omg this is so annoying why are you doing this
Discussion
Possibly to crank the difficulty adjustment and then drop the hash rate off a cliff when they quit attacking?
Interesting. What I described wouldn't even work.
I had to look up the claim about the difference in difficulty scale, because that was new to me, and I've been using the same code for testnet bits/target/difficulty calculations as those for mainnet.
The statement was added here, in January 2011: https://en.bitcoin.it/w/index.php?title=Testnet&diff=2244&oldid=2212
Testnet3 genesis was in February 2011: https://mempool.space/testnet/block/0
Within the current difficulty period on testnet3, I can find no regular-difficulty block that has a hash outside the supposed target using mainnet bits/target/difficulty calculations. The difficulty scale must have been different on testnet versions 1 and 2, but changed to the mainnet scale in version 3.
For a second I thought that was Liquid BTC mempool