Oh yes, didn't read to the end
I was curios and read the documentation and as far as I understand it doesn't work (that easy?).
You always have to change to the needed keyboard layout, to use that shortcut method to insert a word with non-standard characters!
On my German keyboard it is possible to insert an acute accent like é í è á and so on by typing first "
´" then the character.
The keyboard layout is called in this case "German (dead grave acute)".
Maybe you have the possibility to play around with the keyboard layout and variant, like Hardware →Model (in may case on an old laptop to test, with an English keyboard, a x61s) →T61,Layout → English us, Variant → Czech, Slovak and German(US) ←, I get on the 3rd level an "
í ". ( No I am not posting from that test/spare-laptop, but it works by using the caps lock to choose the 3rd level).
Hope that helps a bit.