Miners don't need subsidies. If mining becomes unprofitable at a certain difficulty, they will stop mining. adding subsidies is a way to artificially inflate their revenue and keeping them bloated.

The block subsidy is going to be 3btc. that's a lot less than 500 btc but 3 btc at 30k is worth more than 500 btc at $10.

We shouldn't worry about miners. there is an extreme tendency for miners to grow and they have grown much over the last few years. contraction is natural and necessary to ensure the mining difficulty remains where it should be.

no need for new BIPS.