I like the idea of these features, but the "run this random shellscript from the internet" part really bugs me.
Could / will you integrate it another way when it comes out of the nightly releases?
Totally reasonable thing to ask, but if you'd scrolled down a few more pixels you'd have had your answer. Directly underneath:
The easiest way to install shell integration is to select the iTerm2>Install Shell Integration menu item. It will download and run a shell script as described below.
...you'll see:
"Don't care for piping curl to bash? Do it by hand. First, download the right script for your shell...."