Hi,
"(Is it still an option for the Board to do this and appoint Eliane, Mike, Pascale and Ivan and then skip next year's planned election?)"
Unfortunately, that's not how STV works. Given a different number of seats to be filled would had produced a different quota, which would have resulted in different surplus reallocation that may have produced different result. If this election had 8 seats, instead of 14 rounds of elimination before Rosie & Victoria meeting the quota, Dariusz would have met quota in the first round. The system is not meant for appointing last eliminated if subsequent vacancy opens up.
Regards,
Katie