To me “Synced” is too developery to be helpful. Sure, it accurately describes the technical process but a good name is one that doesn’t need an explanation. It’s like a joke you have to explain, it’s not funny anymore.

I like Yui suggestion of “My Blocks”. Sure, it’s a bit vague but I think it really captures the feature. Its a block or collection of blocks that I’ve set up.

I’m also curious if there is any data on how people use that feature. I’ve never used it for it “syncedness”. I treat it more like a custom pattern generator. I save a snippet that I use a lot. Add it to a new post and then convert it to a regular block. To be honest, I don’t see much value in a block that is synced. That almost seems like FSE territory.