UV_STAT handles Mosaic like Single-Field for the weighting (BEAM, BRIGGS, TAPER and WEIGHT arguments): all visibilities are considered, in- stead of those of one among the various fields. Accordingly, the predicted beam sizes are often underestimated compared to what UV_MAP and FIT commands would yield. For a fine adjustment of the beam shape and size, it is recommended to ver- ify using UV_MAP and FIT commands and iterate if needed.