As I said above, which will be more fun?
That's the main consideration.

Boosting will be faster, no question about it.
During RAF, with triple instance kill experience -and- triple quest experience...
Boosting is the faster of the two methods.
So if we reduce experience from both methods by the same amount (divide both by 3)...
Then the faster method is still faster - but the difference between the two is only 1/3rd of what it was.

I would probably go method A on two teams, with method B on one team.
And go Method A, Method B and then back to Method A.
Just to mix it up.
And regardless of which is faster, go for what is most fun.