They're not great subjects for hanging baskets, but may do okay for a season in a container - biggest risk is vine weevil, for some reason, heucheras are particularly attractive to them.

That seems to make sense. I had heard it said by some people (was it Gardener's world magazine?) that they are good features for baskets. Quite trendy I suppose, but like you say, perhaps not practical. So vine wevil happens in pots more than in the ground. I do see the beetle in my garden every year - dark grey thing. But I've never encountered a grub of it in the seven years I've gardened this spot, so I reckon I'll hope it to luck. I'm sure they are going to look splendid.