I actually like this way. I prefer working on a post basis. And it is not a creative website, just casual. I do have a theme. But for me, what people want of consistency in the theme makes my post editing more difficult. If I want to edit the block, considering the block context, I should not need an external page to do that (the theme). I can only do that as it currently is.

I believe my commentary adds to the discussion the person of the admin, important too. The person that choses the theme, should not be locked by it. As the admin of a website, I want myself to be able to adjust the theme and the content.

Themes should be able to disable features (as it currently is for this experimental spacing) on a block basis. By doing so, admins should still choose to disregard the default position of the theme on a single small feature. On the theme settings, admin should be able to turn off or turn on the way its theme considers the relevancy of this experimental feature.

It should not be difficult to do create that mechanism. Themes that don't want to even allow this granularity to admins simply don't offer it, and the mechanism ia set as "default".
Best for everyone. What we have here is a difficult choice: which side of the coin.