Did you solve this?

Nope. Still want to do it though.

And I also didn't get any notifications here when you replied. Weird.

We have the same suggestion for property controls, the ability to always render despite the value being null. We are thinking about adding a new interface that works for both property controls and block controls that would basically delegate the responsibility to the control. The best solution would be to just always delegate to the control but that, as we found out during testing, was a bit too breaking for existing solutions. Can't promise when we get this in but any suggestions or ideas you have, let me know.

One thing I have thought of for just solving Johans problem right now is that if you have a non editable property (for editors) in the local block and set that property to a value in setdefaultvalues on alla page types that have the block. Haven't tested it though and if it works its a royal pain in the ***