Regtest uses 150 blocks for the reward-halving schedule. Testnet and mainnet use 210000. Why? I thought the whole point of regtest was to have a network that was essentially identical to testnet but without proof of work. If so, it does not make sense to have this parameter be different from testnet.
Is there a reason that this was set to 150?
Related: #8623
Regtest was, as the name implies, added for the regression tests. The interval was set to a lower number for more efficient testing of the reward halving logic. Generating 210000 blocks would take ages even at the low difficulty of regtest.
If you need something else you could use #8623, patch the number in chainparams.cpp, or even add an additional chain definition.
At some point it would be nice to be able to load chain parameters for testing from a configuration file.
Closing this as it isn't really an issue but a question.