There's nothing logical about that to me. Double/triple click? No one outside the flashlight community would have a clue how to use these lights (and I own a handful).
Sequential click through low/med/high/off is intuitive.
I have labels on some lights so people can use them. Imagine that, having to read a label to use a flashlight. Oh, that'll be great in a power outage.
As others have said, the Pixel line is the easiest if you want to have full control over the phone.
There are others, but it will take more effort to get there (I say this after flashing and rooting all my phones since 2010).
Take a look at lineageos.org/devices to see what devices they support, it's a good approximation of which phones can be boot loader unlocked.
After lots of looking around, I decided to finally jump to Pixel, and I'm running DivestOS (a fork of Lineage with a little bit more tweaked, like sandboxing MicroG).
Once you decide to go down this road, I'd suggest downloading the factory rom image for your phone, and practice flashing it, before trying with a custom rom, just so you have some experience with a known-good image. Plus, sometimes you have to flash back to stock - I just did one the other day because I screwed up the custom rom flash.