Any character fate you would change?

Within reason, of course. As in we can't drastically alter the plot too much.

Personally, I would have Chief go find Hotdog and co-parent together, out of respect for Cally's memory and what time he did share with Nicky.

We do see Chief straight up kill Tory in the CIC when it's revealed she murdered Cally, so obviously there are some lingering feelings there, even if Boomer was "the one".

I don't want Chief to be alone.