If you cant feel that joint valve fine. As for crazing . Is there a big door patio or bi fold in that room. That's had a warm breeze blowing in
Bungalow , loft been stacked for years , screwing most of the ceiling every 3 " , nail pops everywhere , some areas need 50 mm to reach the joists as boards were put up with small head clouts and have dropped ,Haha just follow it.
If it ain't flat.
Artex it lol
Had it last year skimmed a conservatory out by the folding doors where the sun was beaming in in the wall it crazed to f**k I explained it to the customer he was sound about it though it paints over fine
She sounds like a battle axe just make sure you get paid when it's done thoughNightmare isn't it, I've told them to give it a light rub with some fine sandpaper and it will paint fine, she turned round and said well it wasn't a warm day when you did it, then her son said the next morning it was like that, told him the same about the heat and he was fine about it (its his house).