Is there any way of setting / forcing a default image transform for images inserted via rich text blocks? I have an image transform that is designed for images inserted into posts, and I'd like to make sure this is always applied to any image in a post. The problem I'm having is that for images inserted via Rich Text Fields, selecting a transform is optional, and the wrong transform may be selected.

Ideally I'd like to set a default transform so I can tell content editors that they can insert images directly into posts and don't need to do anything with the "Select image transform" option... is there any way of doing this, though? Any help or advice would be much appreciated!
I don't think it's possible natively, yet (as of 2.3). However, the ImageSmith plugin addresses this need by providing a 'bulk transform' Twig filter which detects images in HTML, applies a specified transform, and rewrites the HTML to reference the transformed images.