Description of the need
Since we are not making any progress on coming to a consensus about fixing CSS in Basis (https://github.com/backdrop/backdrop-issues/issues/4167), I'm inclined to begin to advocate for a new theme in core that we can eventually use as a default theme.
In my view, many UI or potential design improvements are on hold because of lack of any consensus on how to implement CSS changes to basis.
Proposed solution
Add a new theme to core that assume one of the following:
1) Take our time and try to get it right, recognizing that we will have the same inability to fix problems with this new theme, once it has been committed. 2) Make it clear that this is a DEMO theme designed to showcase Backdrop and that we will be making breaking changes to it. Users should only use this theme if they are willing to accept the risk or willing to fork it and use it like a custom theme (no updates). 3) Build this theme with the idea of supplemental stylesheets (https://github.com/backdrop/backdrop-issues/issues/4512) or supplemental selectors (https://github.com/backdrop/backdrop-issues/issues/4782) in mind from the outset.
Recent comments
Thanks for those ideas. Here is what I'm doing now that works. This adds the video_filter to the config file. $format = filter_format_load('filtered_html'); $format->filters['video_filter'] = (...
How to programmatically insert an array into config file
The port of Organic Groups is within days (if not hours) of a beta release. Feel free to help test and report issues. https://github.com/backdrop-contrib/og
Porting Organic Groups module to Backdrop
I agree with BWPanda about the better way to add a filter. As for your general question on how to add an array to a config file (which gets stored as json), have you tried: $config = config('...
How to programmatically insert an array into config file