Sass 7-1 architecture global mixins

Question

I have my stylesheets set up with the sass 7-1 pattern, and I've eschewed @import in favour of @use and @forward.

I want to avoid using '../..' relative directory pointers, by having a global identifier for common elements such as mixins. I'm using css custom variables for color values, but mixins are not something I can convert to variables.

└── stylesheets/
    ├── abstracts/
    │   ├── mixins/
    │   │   ├── _box.scss
    │   │   └── _index.scss
    │   ├── _colours.scss
    │   ├── _function.scss
    │   └── _index.scss
    ├── base/
    │   ├── _settings.scss
    │   ├── _typography.scss
    │   └── _index.scss
    ├── layouts/
    │   ├── _frame_layout.scss
    │   ├── _content_layout.scss
    │   └── _index.scss
    └── main.scss

and

  /* mixins/_index.scss */
@forward 'box';

  /*  abstracts/_index.scss */
@forward 'colours';
@forward 'functions';
@forward 'mixins'

/*  main.scss */
@forward 'abstracts';
@forward 'base';
@use 'layouts';
.... more content type scss

However, down in layouts/_frame_layout.scss how do I reference the `box' mixin?

/* frame_layout.scss */
/* I don't want frame_layout to know where box lives, relative to the layouts folder */

.piece_of_content { @include ????.box;}