Balmer absorption lines (Dressler & Gunn 1983; Wild et al. 2009), due to the strong contribution from A stars, but until recently very few were spectroscopically identified at $z>1$ (e.g. Vergani et al. 2010). Two photometric methods have therefore been developed to identify this population. Whitaker et al. (2012) used medium-band photometry from the NEWFIRM Medium-Band Survey to identify “young red-sequence” galaxies using rest-frame UVJ colour-colour diagrams. In Wild et al. (2014) an alternative approach was used, based on a Principal Component Analysis (PCA) applied to the deep multi-wavelength photometry in the UDS field. Three spectral shape parameters (“supercolours”) were found to provide a compact representation for a wide range of photometric SEDs. In addition to cleanly separating quiescent and star-forming galaxies, the PCA method identifies “post-starburst” galaxy candidates in a distinct region of supercolour space, corresponding to galaxies in which a significant amount of mass was formed within the last Gyr but then rapidly quenched. The method was recently verified with deep 8m spectroscopy from VLT, which established that between 60% and 80% of photometric candidates are spectroscopically confirmed post-starburst galaxies, depending on the specific criteria adopted (Maltby et al. 2016)[^2]. In terms of completeness, the photometric method was 