Well as predicted it's a nightmare.
Spent 4 hours filling cracks and then when it came to checking it was dry next morning realised that it was actually flexible filler I'd used, which would have been OK had I smoothed it all off, but I hadn't. I thought we could sand it down, but no, it was just like rubber stipple. It all had to come out, which took fucking ages. So, about 6 hours of work completely wasted, with another couple of hours planned to refill so as to get back to the same point.
Anyway mustn't grumble, the rest of the day was great. Just the fridge and the land phone that decided to pack up at the same time yesterday.