You could use US Intl. keyboard layout and use RAlt+z/l/w for æ/ø/å. If you have a QMK Firmware keyboard you could even reprogram it to use Alt + '/;/[ to send

You could use US Intl. keyboard layout and use RAlt+z/l/w for æ/ø/å. If you have a QMK Firmware keyboard you could even reprogram it to use Alt + '/;/[ to send these keys and you'll have æ/ø/å in the usual position.