Ella

> For instance, we have various features where we need to show a table with multiple columns of data to our users. Could you tell up more about what this...

Why do we need to check fills? Don't we always need to render the switcher and options buttons?

Not sure I get this. To me the should always be the block icon visible? For this PR specifically, can't you check first if there is anything else to render...

Could you still do other checks first to fix the performance problem?

I have the same problem

This is an enhancement, so punting to WP 6.7.

@Mamaduka Right, that's a good point. I don't like keeping onSplit though, maybe you should be able to opt-out of attributes in the block supports key? Or opt-in? What do...

@Mamaduka I meant, how to incorporate it in the new way?

> A good example would be the button block. Currently, it copies all attributes on the split action, including URLs. Which I think is a bug; only styling attributes and...

Feeling great about this change. Let's merge and iterate, it's good to have some testing in the GB before we have this in WP.