Graphiti’s architecture is solid and basically unchanged since the basis of the framework was already productive within SAP SE for several years. There were no changes from architecture point of view in the 0.13.0 timeframe.
Some parts of the framework coding needing some rework (e.g. in the rendering area) could not be addressed within this release and will be targeted for one of the next releases.
Graphiti will stay in the incubation mode. The reason for this is that there are too many open questions with respect to upcoming support for e4 RCP applications and the upcoming GEF4 version.
The currently used GEF 3.x rendering appears to work fine but has several shortcommings/issues with rendering, e.g. off-by-one-issues. Fixing them would mean to invest massive effort within the Graphiti framework.
GEF 4 or JavaFX offer themselves as alternative new rendering engines with much more future potential, but switching Graphiti to one of them also requires huge effort first in investigating these alternatives and second in writing a completely new UI layer for one of the frameworks.
The second alternative appears much more promising and seems to be the way to go. Unfortunatly, for both things there is currently no capacity in the available development resources. Unless there is much more engagement in framework development for Graphiti we can only stick to the current GEF 3.x based rendering engine and live with the limitations.
Leaving incubation should happen only after the new rendering engine is in place, because that change will require massive API changes throughout the complete framework.