Yes, I am still alive, don't worry. Thanks for asking.
It is correct I am busy on other projects at the moment.
The builder will evolve as soon as I get more time, or maybe a team to help me.
There has been some such moments like this, I am very excited with Joomla 4, but there is no rush until it is gonna take long before all websites evolves.
The next upgrade will be the Joomla 4 compat, it is a long way, I started it already. PHP namespacing is alreday working but there is so much work ahead the achieve.