Mm right, that's a pity. If / when I'll be building and testing my own miner, I will then probably just change that constant and recompile it so that I can achieve e.g. a 1 minute block time to verify that the device is working as expected. But it would be cool if it was self-adjusting like mainnet every 2016 blocks. Maybe even with an optional flag that sets the block time target (e.g. 1 minute for testing purposes instead of 10).
We have 4 networks (I'm not familiar with Signet so I will skip it).
- MainNet where difficulty adjusts each 2016 blocks
- TestNet where difficulty adjusts each 2016 blocks but on every block the time is checked and if there weren't any new blocks in the past 20 minutes it falls down to minimum difficulty = 1
- RegTest where there is no difficulty adjustment and the target stays at lowest value to allow blocks to be mined within seconds
Each of these networks serve a different purpose, eg. TestNet is there to mimic the MainNet but at the same time we don't want to cause a huge gap between blocks if difficulty were high and nobody was mining it anymore. RegTest is there to allow you to quickly acquire any amount of [test]bitcoin and be able to test anything without needing to experience a bottleneck caused by mining.
