9line
As I have said few times earlier too, there is a major difference of bootstrap version in current and upcoming builder and we would want to support the new builder for one version of Joomla only. The current builder is saas model based and need communication with our servers for loading new elements and while it has its own merits but based on user feedback the model is not practical, so the upcoming builder is standalone.
The new builder will have all the blocks and library supported by current builder, so that users would be able to move to new builder easily.
If there are any bugs in the current builder, we will fix them on priority but feature requests will be released only with the new builder.
We expected Joomla 4 to drop in by now but it is still in alpha. We will release the preview of T4 and New builder as Joomla 4 goes beta / RC stage.
Thanks for your patience.
Regards
Arvind