So Flurry axe doesn’t give you and extra attack like it says. It gives no visible buff and just instantly swings your mainhand. This isn’t giving you an extra swing, it just skips the swing time for your mainhand. Theoretically you could use this and swap to a 2hander after getting the proc.
So on further testing with the weapon it is very possible. You can swap weapons right as you swing. The first hit will be with the axe an d the second will be with the weapon you swapped too. You can even use seal of command and get the second weapons stats for the abilities proc. Seems like the damage for the procs ( both Flurry axe and seal of command ) are calculated .5secs after the swing. This allows you to swap weapons get a free hit with say OEB and get the seal of command proc for that weapon.