Another option to bring difficulty down is using Mining rig rentals looks like it would take between 0.1 - 0.2 BTC to do so.
Start with a 3 or 2.5 P/hash 3 hour rental - extend until blocks are found difficulty adjust, then drop the hash rate again and repeat until it's back to normal
Using Nicehash to get down to 1 P/hash may be a better option, then using Mining rig rentals to bring it the rest of the way down
out of the two options I say
Option 1 - switching to GPU friendly algo would be better
This is exactly what I knew would happen since 2014 with more and more gpus, fpgas asics entering the cryptospace their would be large amounts of easy hash and those who purposely try to derail projects or noobs that don't understand how to use hashing power effectively. There was a group I believe in 2015/16 that was using a large gpu farm to extort BTC from devs.
Although it's to late now, the good option for any new POW coin that most don't even realize has been around for awhile is doing a
POW/AUXPOW using the Blake258 8 round algo.
Merged Mining is one of the most efficient ways to mine. While the blockchains remain independent from each other the hash rate is applied fully across all chains.
Bitcoin was the first to introduce merge mining but
BlakeCoin has taken it to a whole other level. There are currently 5 child chains mining along with BlakeCoin but room for 200 more to
join in the merge mining .
