@DAreRodz shared the following feedback with me in Slack:

I have a couple of questions regarding directives evaluation and wp-context:

I see that directives run inside wp_process_directives(), a callback added to the render_block hook—dispatched every time a block has rendered—, and uses WP_HTML_Tag_Processor to iterate over the HTML content, find the directives, and execute them.

The questions are:

1. Isn’t that callback running several times for the same HTML?. E.g., if you have a block A and a block B inside A, both blocks will dispatch render_block when rendered. Won’t B's directives run twice, one when render_block is dispatched for B and a second one for A (that would include B in its $block_content)?
2. WP_Directive_Context is instantiated for each render_block execution. Doesn’t it create a different context stack for each block? I guess it works in the end because we run directives inside inner blocks again (as mentioned in question 1.)?