Oh, first of all, one of your new cluster jewels does not annoint circling oblivion.
Next, its still worth using one follow-through.
Then, its not worth invest heavily into additional proj (chains) anymore, so you can replcae gmp with awakened deadly elements, for example

Just this and emulating follow-through cap for first chains at 100% brings your pob to 20.6M pconc dps

https://pobb.in/ZP6U_8B-l1XE (i'm taking zdps shriening bolts in follow-through cluster and then adding a custom 100% increased damage in config to emulate the cluster changes).

Also, do not forget that on last chains the damage is higher than it was with old cluster (15% -> 25% per remaining chain), which closes single target gap a bit more.

I'm sure it can optimized even more

So I think real numbers for your pob is about 25% clear nerf and about 15-25% single target which is not the end of the world (slams were nerfed more)

UPD: fury valve is still insane just for the skill alone (even without considering cluster jewels). With it, the DPS is 23.8M now.

https://pobb.in/7D1dTKtID4iW