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Thank you! ❤️

Something else we'd have to consider as a part of this stream is how to handle things if the block being inserted is already present in the content? I don't think the block should be auto-inserted in this case (when multiple:false).

I remember we discussed during WC US that sometimes plugin developers would like to decide whether the block should get auto-inserted only once, but not necessarily in the first matching spot, but maybe last. I believe we should build a general function that performs basic checks informed by existing block API, and integrate a WP filter to offer ways to prevent insertion based on custom conditions.

I believe we should build a general function that performs basic checks informed by existing block API, and integrate a WP filter to offer ways to prevent insertion based on custom conditions.

I like this approach, we would need to ensure there is any helpful context provided to the filter (outside of what may be exposed globally by WordPress to callbacks).

I left a comment that contemplates on the complexity of adding support for supports.multiple and other similar existing APIs for blocks in #53987 (comment).

To reduce clutter, I'm going to close this PR - it was always intended as a reference POC and has generated some useful discussion :)

Thank you so much for starting this PR to gather all the insights.