My installation did the something at the exact spot I thought it was frozen but after a few minutes it started moving again and then it showed the estimated time remaining.
Still the same, although a few reports of it hanging like that for a long time. Looking at an hour now without it moving. Need the laptop for work again tomorrow. Really frustrating
So I pressed the power button and it said “your mac will reboot when update completes”. It then came up “about 9 minutes remaining”, now it’s gone back to estimating time remaining. What a relief there are signs of life, fingers crossed.