Model-Driven Engineering has got a foothold in industry as an effective way to tame the complexity of modern software which is meant to run on embedded systems with real-time constraints by promoting abstraction, in terms of prescriptive models, and automation, in terms of model manipulations. In the plethora of modelling languages, the Unified Modeling Language (UML) has emerged and established itself as a de facto standard in industry, the most widely used architectural description language and an ISO/IEC standard. In the SMARTCore project we have provided solutions for UML-based development of software to run on multicore embedded real-time systems with the specific focus of automating the generation of executable code and the optimization of task allocation based on a unique combination of model-based and execution-based mechanisms. In this paper we describe the lessons learned in the research work carried out within SMARTCore and provide a set of perspectives that we consider to be highly relevant for the forthcoming future of this research area to enable a wider adoption of UML-based development in industry in general, and in the multicore embedded real-time domain in particular.