The Netherlands should be highlighted for ë but isn't

They've split Finland pretty arbitrarily into areas where (supposedly) Swedish speakers are found for 'å', but there's really no reason for it. The letter is a part of the Finnish alphabet and taught to everyone in school, so it should cover the whole country I think.

Ireland should be highlighted for Éé

Swedish uses é

All Polish letters are included. But I don't understand, why a small piece of the ocean is marked along with Poland in "Ż".

Edit: I checked, it's Malta.

English definitely uses æ even if rare

ironically the use of those in spain everyday is way more common than the use of the Ñ

Also ü for Spain is missing, uncommon but definitely used and important.