Set preset image size (and maybe alignment) for gutenberg editor

In the old editor the preset/default size of an image in the media libary could be changed with some php but this doesn’t seem to work anymore in gutenberg.
Is there a way to set the default image size to “full” instead of “large”? I thought about extending the core/image block myself but I can just override and don’t know how to replace defaults.

• This topic was modified 5 years, 3 months ago by Jan Dembowski. Reason: Moved to Fixing WordPress, this is not a Developing with WordPress topic