Settings already allows you to "tune your lockdown mode" to suit your preferences. For example Settings > Messages > iMessage is literally a switch to turn off

Settings already allows you to "tune your lockdown mode" to suit your preferences. For example Settings > Messages > iMessage is literally a switch to turn off iMessage if you feel that it's problematic. Settings > Safari > Privacy and security has various settings which allow you to have a 'more fine tuned lockdown' for safari.