With US International, unless I want to hit the key combo to change layouts, I can still write a single or just a few umlauts (say, for a person's name).
I find it easier to keep my focus when I don't have to make the right wrist twister that is otherwise required for { if using a Swedish layout.
The extra key on the UK layout brings # without shift, which is useful, and £ and ¬ which presumably aren't, but could be remapped to something more useful like € and an accent.
In my situation I write in english, swedish, danish and sometimes icelandic as well as in programming languages. My solution has been to create my own keyboard layout that I call Nordic Programmer which is the US keyboard but by pressing altGr I have åäö letters where they are supposed to be, and øæ next to them. and then on altGr+eyuioadt i have éýúíóáðþ for icelandic. All of them are capitalized by adding shift. This was pretty easy to learn to use and makes me not have to switch keyboard all the time. It is not truly nordic I guess, because it prioritizes swedish which is the keyboard I learned growing up.
