drupal 8 Sub-theming with bootstrap

I have installed bootstrap theme in Drupal 8. Later I have installed a subtheme with the sass version of the starterkit.

If I install a subtheme with the cdn version of the starterkit I can select diferent themes from jsDelivr cdn provider.

Sass version starts with the default theme style. Is it posible to start with a diferent theme style like “Slate” for example, and start to override the styles from it?

Thank you.

Drupal version: 

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