Do you think that the barometer/altimeter will be better then F3hr or even F5?
Or more likely, do you think, that the watch will callibrate it's altitude based on the topo maps? If so, the device will be very accurate. What is your opinion?
There is another thing to consider... if you forgot watch in fixed barometer mode and during this period there is a change in atmospheric pressure, when you will go to adjust altitude, barometer will be off in proportion to athmospheric pressure change...
I think if you want to calibrate barometer that is off by "+" value, you have to fix barometer in "altimeter mode", hope that atmospheric pressure will rise and than calibrate altimeter again