This is great, I've been using Sublime Merge similarly in my workflow. I stage individual files while drafting the commit message and make sure to split lines across commits for logical rollbacks. I personally find it a lot faster than using the CLI, at least in this case.
I specifically love committing individual lines in a hunk and leaving the rest not staged until I am good and ready to stage them. It's been a great addition to my workflow and makes self reviewing my stuff easier before I go to send a PR.
Same here, I’m a tmux junkie but for the particular use case of staging smaller parts I much prefer sublime. Have been meaning to give fugitive a proper try as well, looks like it’a gui allows for a similar use case as well without the context switch.