How do I disable the cache for the Bootstrap theme? [duplicate]

Im running Drupal8, Bootstrap3 custom sub-theme using SASS(scss). I cant manage to Disable the Cache. Right now in order to see any CSS Style changes i need to Clear all Caches.
Other non-Bootstrap themes have the cache disabled.

I’ve followed the following instructions to disable Drupals Cache:

There is a similar post asking this here(Disable caching (for theme develoment) doesn't work), but even though i’ve followed the instructions in that post, it does not solve my problem.

In settings.local.php i have:

$config('system.performance')('css')('preprocess') = FALSE; (tried 'TRUE' also)
$config('system.performance')('js')('preprocess') = FALSE;  (tried 'TRUE' also)
$settings('cache')('bins')('render') = 'cache.backend.null';
$settings('cache')('bins')('dynamic_page_cache') = 'cache.backend.null';
$settings('cache')('bins')('page') = 'cache.backend.null';

My looks like this:

  http.response.debug_cacheability_headers: true (tried 'false' also)
    debug: true
    auto_reload: true
    cache: false
    class: DrupalCoreCacheNullBackendFactory

Under admin/config/development/performance

Bandwidth optimization: both Aggregate CSS and JavaScript are unchecked.

Is there specific Cache configuration for Bootstrap? Or is there something else? I cant seem to find anything about Disabling Cache in the documentation.

Thanks! (Happy New Year’s!)