Getting the ball rolling. Which VB6 projects are you working on?

[yereverluvinuncleber]

What is ultimately missing is a corresponding XAML designer for VB6 or for TwinBasic that creates the XAML string.

That is what is needed, we have the TB designer, perhaps the first step is a converter from the (JSON?) format that it creates, into a XAML format.

There must be, somewhere, an open source graphical interface designer that could form the basis of a separate designer that can handle the extended capabilities of XAML based forms.