To be honest I don't think we need more than 12 columns. Bootstrap grid can be subdivided. This means that you can take any column and subdivided it into 12 columns.
This is specially useful in situations where you want to create a main column and a sidebar, and then divide the main column again.
The example you are showing is a table, and I think Taos solution is correct. Although it is possible I wouldn't use bootstrap grid on a table since tables are already divided into columns. In order to achieve Taos solution, table layout should be set to fixed. https://developer.mozilla.org/en-US/docs/Web/CSS/table-layout
If for any reason you absolutely need to divide the grid into 24 spaces rather than 12, and change the gutter from 30px to 20px as suggested in the comments, you can easily do it by changing these 2 variables:
I've never tried it and it'll probably affect other patternfly components.
Let me know if Tao or you need help to implement any of these,