The blockexplorer says Clever finds blocks in a few seconds. The truth is that they might find blocks much faster (about 12 blocks within a second?). That's faster then the blockexplorer can proces. I saw around 12 blocks with age -1Y at the same moment. Why is the algo allow that?
The difference in power between dedicated miners and Clever is way out of control. Boosting the dedicated miners I see as only solution. If we manage to mine the hard blocks quicker then the diff will not fall that much.
The timestamps are in the block itself. The block explorer can easily process 50 blocks per second.
The "-1y" is a feature in displaying time that is in the future.. The timestamp in a block can be set in the future when the miner doesn't have his clock synced properly.