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The three nearly pure hydrogen WDs G191B2B comma GD153 comma and GD71 at V=12-13 mag provide the basis of the HST flux calibrations for all the HST SIs comma but fainter secondary standards are required for the WFC3 and ACS cameras comma for COS comma for JWST and the Roman Telescope comma and for the general astronomical community. In addition comma new CCD observations in comparison with archival STIS data will provide an update for extrapolation to modern times of the ancient Goudfrooij et al. (2006) CTE correction formula. A comparison of G430L vs G430L-E1 will also aid in constraining a revised CTE correction formula. While three of these stars are well modeled with the new pure hydrogen WD grids (Bohlin et al. AJ 2020) comma Detlev Koester has agree to provide an updated He model for WD0308-565 comma which provides essential extensions of the SED below 1150A for COS and into the mid-IR for JWST. Three important faint WDs were observed in Cycle 27 (16028) with a 12 orbit allocation but augmentation of those data is needed to achieve the minimum of three independent repeat visits that are required to average over the instrumental repeatability (Bohlin comma Deustua comma and de Rosa AJ 2019) and to confidently define a high S-N flux standard comma especially for the CCD modes. These stars are WD0308-565 (V=14.07) comma WD1057+719 (V=14.68) comma and WD1657+343 (V=16.1). In addition comma SDSSJ151421 (V=16.5) is a new standard from Narayan et al. (2016 comma 2019) and Calamida et al. (2019) that provides a crucial tie-in to the even fainter WD all-sky network (Program IDs 12967 comma 13711 comma and 15113).