This doesn't apply to your specific route, but it is very possible to find five or more premium award seats on certain airlines, particularly when it's getting closer to departure date.

For example, Swiss often shows (through Expertflyer) 9 x business seats available and often multiple (greater than 2) x F seats. Right now, you could get 5 x F seats and 9 x business seats on LX64 ZRH-MIA on 13 April.....

Edited to add: There's a similar availability profile on LX between ZRH and NRT in a couple of weeks, as well as availability of at least four seats in business on the NH and UA connecting NRT-HNL-NRT flights, so it can be done.