Justin! Thanks as always for diving in and making each task your own. I sometimes loathe making these sorts of things so... specific. I much prefer folks get inspired and take the exploration in their own direction so thanks for doing just that.

Like you, I am loving seeing the WordPress photo directory grow. I submitted a photo right before writing this. I'm a long time Pexels user so, the second I can start filing feature requests, I plan to go wild sharing what I'd love to see in the long term.

Since you were playing around with duotone, I'd be curious to have your thoughts on this issue I opened in light of Paal's feedback on the exploration: https://github.com/WordPress/gutenberg/issues/38556

However, I would like to see a range of filters available to users. If this is too much for core, perhaps a standard filter-registration system for developers might be in order.

I totally agree with your take of things there. For now, I'm going to highlight this in my recap summary post but not yet open an issue for it as a feature request.

Implementing the border options across the range of media-related blocks is low-hanging fruit. Captions should be a dedicated block with a range of typography and color controls. Padding and background color options for the wrapper around images would allow users to “frame” their photos:

To quickly connect some dots on these rapid fire items:
- Border options: https://github.com/WordPress/gutenberg/issues/21540
- Captions as an inner block: https://github.com/WordPress/gutenberg/pull/31823

For framing, can you say more about the intent there over using the border options? I want to be sure I understand the distinction.

I want to use my post’s featured image in any image-related block. I have long requested the ability to drop them inside of a Cover, for example.

Big yes. Right next to this top request (which is covered nicely in the rethinking featured images issue you link to) is the constraining featured images to a ratio: https://github.com/WordPress/gutenberg/issues/35524

Thanks for these interesting thoughts and neat examples. As a photo lover, it makes me excited to think about what could be possible just reading over your response!