Is there a better way to use git update-index --sk

Question

I know with a version-tracked file that is "ignored" using update-index --skip-worktree git will detect and not merge any incoming changes to files that are marked as such.

The process at this point would be to no-skip-worktree the file, stash it, perform the merge, then apply the stash, and then re-skip-worktree the file.

I wonder if there is a way to make this less tedious. I think the way that stash works as a stack helps with this. So it would be a git alias that executes 5 commands and takes one argument (the skip-worktree file in question): stash the first arg, merge passing the remaining args, and then apply stash.

I think i have answered my own question, but I'm wondering if there is a more elegant way to implement this. for example this still requires me to re-enter skip-worktree file in question, when perhaps it would be best to just automatically detect all of these and stash all of them. But there is also some more sanity-checking that should be done... it's starting to turn into a multipurpose force-merge alias command now.

Furthermore there is the issue of tracking different changes. for instance i have a situation now where I want to keep a block of code that exists only for me, but sometimes I want to also make changes to this same file that I actually have to commit. So it gets a bit messy as now I have to basically change the skip-worktree nature of the file ahead of time and stash my "ignored" changes, and put them away until I'm done making my final change to actually commit, then go do all of that and then apply the stash, and then set assume unchanged again...

I think what I want is for git to actually be able to track for me these assume unchanged changes at a code hunk level instead of at the file level.