Extend layout field for n/5 or n/10 columns

I have a page with only 10 columns and can’t use the 6 or 12 column grid settings in the layout field. Can I extend it so it allows 1/5, 4/5, 9/10, etc.?

Thanks for any guidance.

Maybe for now I’ll just use the existing base 12 layout system but make the conversion to base 10 in my CSS.

I’m finding a need for this again. Could I go about extending the kirby/src/Cms/LayoutColumn.php class in a custom plugin? I’d start by reducing the $columns there to 10 instead of 12. After that, replacing the fractions in the layout blueprint is quick, so should be customizing the CSS in the panel.

EDIT just added to nolt: https://kirby.nolt.io/625