Petre My calculations, as it turned out wrong, were at the brew boiler, 40 mls leaving at ca. 105 deg C and 40 mls entering at around 20 deg C (if not plumbed in, where it should be 10-15 deg C). As it turns out the Micra has a supply from the steam boiler at 85 deg C so the drop in the brew boiler is not significant.
I agree with your estimation. On my V when I pull a shot the temp in the brew boiler PID keeps at 94 or 95 for the shot, ca. 40-45 secs, and 10 secs later would drop to 93-92 which takes around 30 seconds to be up to 94/95.
EDIT: It has 10 deg C offset