I missed this. You can buy upgrade to Platinum corner if you are gold or J flex tix.
If you are travelling with a Business Classic or Flex ticket or are a Finnair Plus Gold member, you can upgrade your complimentary lounge access to the new Platinum Corner. The price is €30 or 4,800 Avios for adults and €15 or 2,400 Avios for children and you can buy it directly at the lounge reception.
Surely the plan is soon to sell Platinum Wing access also at Non-Schengen.