Just stumbled back onto this thread to take a peek.
I have a few questions because that is abnormally high cc:
1. When was the last time you added AA and how much?
2. Can you list the specific products you added since opening? Want to check something that might be an alternate cause of initial cloudiness. Eg. If EDTA sequestrant was used and then diphosphonic acid sequestrant...
3. Do you use antifreeze in the lines when you close? If so, who opened the pool and did it happen to get flushed into the pool instead of pumped to waste.
4. Have you used any product with MPS in it - potassium monopersulphate? It will/can create false cc readings.
Either way, to trump this beast you'll need to oxidize whatever is fighting the FC to get a good baseline going forward, but you've been at it a while and if we had an idea on these things it might make as much sense to do a partial drain, then continue a Slam if the ccs don't start dropping soon.
The decision to dilute is usually site specific, meaning water table, cost of water, bans on water, etc are all considerations.
But I'm throwing the idea out there in part knowing that you've also had metal issues, so dilution might save you a spot of future maintenance as well. At the same time, a few more sessions of dosing up might nail it...
Let us know and I'll check back and do a lookup on pool store elixirs