I'm running a private Parity blockchain, currently in test mode. There is always a possibility that we'll have to change some initial parameters when the blockchain is live. For example, we might want to disable Ice Age, change block rewards, etc. I know that newer Parity versions support additional parameters in the chainspec file, so it is possible to change it without resetting the blockchain. Which parameters in the chainspec file we'll be able to change and keep the blockchain running?
I believe that you may change many parameters, but the changes will not apply retroactively. So, you may not change anything in genesis block. Also, if you set transition block number option, such as
bombDefuseTransition, the block number must be in future, and if you change/remove transition block number option, then both, current and new block numbers must be in future. Otherwise, your already minded blocks will become invalid and will be dropped from the blockchain.