I have done something similar to OP with my Miele washer. Once you start a cycle it begin filling the drum, and analysing how much water your clothes absorb, at

I have done something similar to OP with my Miele washer. Once you start a cycle it begin filling the drum, and analysing how much water your clothes absorb, at which point it re-estimates the wash duration based on the measured load size. Based on the stats I’ve collected, once it done that re-estimate (which is usually reducing the cycle length slightly), the new duration will be spot on nine times out of ten. Occasionally it take longer than normal to balance the drum for the spin cycle, and I can see the machine adjusting it wash duration in my stats. I’ve also noticed the Miele machine seems I incorporate info from previous wash cycles. So the initial estimate it provides before you hit start, will slowly adjust to match wash duration of your typical load. As a consequence, if the machine says it gonna be done in 1:40, it’s pretty much guaranteed to be done in 1:40, and probably completed in 1:20-1:30. So more than accurate enough to plan around.