How long is the 250% PoS period?
Block 1000-50000 = 250% APR
Block 50000-100000 = 500% APR
Block 100000-500000 = 250% APR
Then percentage will halving every 500000 blocks until from block 2500000 = 7.8% APR
Block time is 2 minutes, so 1000 block is about 1,389 days.According to the PoS breakdown it should be 125%, because the chain is at block 732897.
Note that this is just an assumption, since I don't know if the protocol sticks to PoS breakdown and
https://comp.ccore.online/ block explorer is accurate.
You are right. I am not sure about the exact POS APR but looks like is something like that. Also the block explorer is working good, is at the right height.