Synthesized pieces in sub-models are not propagated to containing models

[j6t]

Consider the following model file:
TestSynthNestedModels.txt (change file extension to mpd).

It contains a sub-model with a flexible hose, which was bent by adjusting the control points. This sub-model is used in the main model. But the main model shows a straight hose as if no control points were modified. The expected result is that the adjustments made using control points in the sub-model are also visible in the containing model.