Maybe I'm misunderstanding what people want an init system for, but I'd expect to need little more than "run these 10 tasks. Potentially, wait for A to finish before starting B". Its job should be over when you see the login prompt.

It feels like modern inits are more like a watchdog/messaging system-- which seems like something which would be an optional add-in atop a real init system.

I want to run a custom utility at power on. It's not a weird expectation. This should take no more than one line of code to achieve, adding "/usr/local/bin/toolname &" to some sort of rc.local file.