Yes, it is safe to swim.
Remember, with CYA that high you need to be diligent in not letting your FC go low. If algae gets a foothold you will be using massive amounts of chlorine or doing another water exchange.
Additionally, no solid forms of chlorine that might add CYA.
In my case I took close to a year getting my CYA from over 200 to the 50 I have today. I probably back washed more often than I needed to and built a system to harvest rainwater form a roof gutter.
Like folks with high CH, it can be managed - you just need to understand it and keep control.
Go swimming, after the last couple of days you deserve it.