We spent four days in Wengen, Switzerland, discussing ideas for physics with the Mu3e apparatus beyond the search for the lepton-flavour violating decay of the muon to three electrons. Collaboration members and theorists presented new ideas for future measurements with the high acceptance, high resolution Mu3e spectrometer using high intensity muon and pion beams at PSI. Technical challenges and promising R&D directions related to high-intensity data taking were also discussed in detail.
