Many modern software-intensive systems consist of multiple components interacting together to deliver the intended functionality. Often, these systems come in many variants (products) and are managed together as a software product line. This variability is the source of additional complexity which can cause inconsistencies and offset the economies of scale promised by product line engineering. Engineers thus need intuitive, yet precise means for specifying requirements and require tools for automatically detecting inconsistencies within these requirements. In recent work, we proposed a technique for the scenario-based specification of interactions in product lines by a combination of Modal Sequence Diagrams and Feature Diagrams. Furthermore, we elaborated an efficient consistency-checking technique based on a dedicated model-checking approach especially tailored for product lines. In this paper, we report on further evaluations that underline significant performance benefits of our approach. We describe further optimizations and detail on how we encode the consistency-checking problem for a model-checker.