If economy is oversold and there are free seats in business, according to my experience Finnair typically upgrades according to status at gate. Volunteering, begging, etc will not help. At checkin they will do not upgrade, however, they might ask if you are travelling alone or not. If you travelling together with someone, they will upgrade both or neither. Usually latter.

OWR is kinda low status depends greatly on route whatever you will be upgraded or not. Nagoya and Fukuoka for example have normally low elite presence, while Shanghai and Tokyo have high.