I just always enable "Show whitespaces" in any editor I use. https://i.stack.imgur.com/BP2WJ.png

This let's me know if I left any trailing tabs/spaces before committing, align code better and while writing not while "refactoring".

git commit -am 'Whitespace formatting changes only'

No.

Don't align.

    void my_function(
        int arg1, int arg2, int arg3,
        ...
    ) {

I also like a rule that states that you either put all the parameters on one line, or each one on its own separate line, but never something in between.

I don't think blindly following any convention is good. Sometimes it makes sense to group a few parameters, take this toy example for instance:

    void drawrect(
        Surface *surf,
        int x, int y,
        int width, int height,
        uint32_t color);

Grouping relevant arguments just makes it a bit more legible. It's even more useful when calling the said function (assuming function with a lot of parameters, say XCreateWindow).

While I quite like that style, now you have to convince people to never align, before you can convince them to use tabs.

I've not seen any large public code-bases uses this style, so it's hard to know how well it works in practice. Do you know of any major projects with a 'no alignment' requirement?

MediaWiki uses tabs for indentation and discourages alignment. https://www.mediawiki.org/wiki/Manual:Coding_conventions

I also much prefer this way of breaking long lines. Aligning parameters always looked ugly to me, specially with long function names.