Why does the network have so much new capacity with this release ?
IX capacity has always been better than PoW capacity, as you're not having to wait for the whole lumbering Proof-of-Waste farce, you're getting consensus from a much smaller group of nodes.
Without PoW consensus I feel like this is becoming dangerous territory: If the subset of elected IX-nodes is small enough, wouldn't someone like Otoh with over 600 MNs have a good chance that a TX is entirely in his domain? What would stop an attacker from reversing an IX-tx before it hits the miners, when all consensus nodes are controlled by one person?
You have it exactly backwards, MN subsetting is tens of thousands of times more secure than PoW.
If there are 600 compromised nodes out of 3000, and you need 10 of those 3000 to beat the system, the chances that all of the 10 needed nodes for any one IX will be among the 600 compromised nodes are miniscule.
Roughly, (600/3000)^10 = 0.000000102
Evil-Otoh will be waiting a long time to bugger up a single IX.
There's a reason hierarchical structures arise in nature and society - efficiency. Societal hierarchies are easy targets for compromise because they are essentially static, they provide fixed targets. Pooled mining is a good example of an this, it's a vulnerability, not an asset.
Overlay networks like Masternodes are a
fluid hierarchy and vastly more resilient to attack.
